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Keys and Bibliography to the Collembola

Family * Hypogastruridae Börner, 1913

Family * Hypogastruridae Börner, 1913

* This family name is adopted here pending the final decision of the International Commission on Zoological Nomenclature concerning the validity of the generic name Hypogastrura Bourlet, 1839. See Science, 1947, 106 (2673), p. 584.

page 8
* Sub-Family Tullberginae Bagnall, 1935

* Bagnall, in 1935, while studying the British Tullberginae, gave one of the characters of this sub-family as "the fact that in no position is there more than 1 + 1 pseudocelli." If this character is regarded as valid for the sub-family, it becomes necessary to separate off Tullbergia trisetosa Schaeffer and Tullbergia australica Wom., both of which have 2 + 2 pseudocelli on some segments, together with Clavaphorura septemseta Salmon from New Zealand, into a further new sub-family. As all these species agree in body form, sensory organ of Ant. III, and form of postantennal organ with the rest of the species of the Tullberginae, I do not think such a separation is desirable.

Key to the Genera of the Tullberginae
1. Sense organ of Ant III entirely exposed, consisting of 2–3 (rarely 4) superior sense rods which are either straight or slightly curved, with their sides either sub-parallel or converging, and two inferior sense rods between them; antennal base generally present and distinguished by having cuticular granules smaller than those of the rest of the head 2
Sense organ of Ant. III protected by cuticular fold or pocket Antennal base generally absent 3
2. Unguiculus reduced, rudimentary Tullbergia Lubbock, 1876 (711)
=Boerneria Willem, 1902 (1138)
Unguiculus well developed Protullbergia Bagnall, 1947 (86)
3. Sense organ of Ant. III with sense clubs or sense rods or both 4
Sense organ of Ant. III without sense rods but with two large papillae, each in a separate but adjacent cuticular pocket, and each bent towards the other; Ant IV without apical sensory knob; pseudocelli of peculiar form Paratullbergia Womersley, 1930 (1160)
4. Sense organ of Ant III with two inferior bent sense clubs, two superior bent sense clubs and two outer large sense rods, the whole behind a cuticular fold; claw with two groups of clavate hairs; unguiculus absent; Ant IV with apical exsertile knob Clavaphorura Salmon, 1943 (914)
Sense organ of Ant. III with fewer clubs and rods; claw without clavate tenent hairs; unguiculus present or absent 5
5. Abd. VI with at least seven spines; Ant IV with two sensory knobs at apex; sense organ of Ant III with 3–4 sense clubs protected by a cuticular fold; pseudocelli almond-shaped, with the border confined to only half the periphery Dinaphorura Bagnall, 1935 (78)
Abd. VI with fewer than seven spines 6
6. Ant IV with only one apical sensory knob; sense organ of Ant. III with two superior, strongly curved sense rods which curve towards each other, sometimes with a single accessory rod, all protected and partially covered by a cuticular fold or by papillae; two inferior sense rods either straight, curved, or clavate, and partly or completely hidden behind the cuticular fold or papillae 7
Ant. IV without apical sensory knob; sense organ Ant III with only one sensory rod, which is blade-like and transversely directed; Abd. VI with 3–5 rudimentary spines Austraphorura Bagnall, 1947 (86)
7. Abd. VI with two branched spines. Postantennal organ with at least 20 fusiform tubercles arranged in two or four rows lying at less than right-angles to the axis Neotullbergia Bagnall, 1935 (78)
Abd. VI with simple spines 8page 9
8. Abd. VI with medio-ventral process and two large anal spines on papillae; postantennal organ with complex bifurcate vesicles set at an acute angle with the axis Metaphorura Bagnall, 1936 (81)
Abd. VI without medio-ventral process 9
9. Postantennal organ with triunguate unilocular lobes; Abd. VI with four anal spines and two spine-like papillae Neonaphorura Bagnall, 1935 (78)
Postantennal organ with elongate or fusiform lobes, never, triungulate 10
10. Postantennal organ with at least 25 tubercles. Abd. VI with four anal spines Stenaphorura Absolon, 1900 (6)
Postantennal organ with at least 20 tubercles: Abd. VI with two simple anal spines Mesaphorura Börner, 1901 (139)
Sub-Family Onychiurinae Bagnall, 1935

* This genus is inserted here following Bonet's diagnosis.

** I can detect no significant difference that will serve to separate Onychiuroides from Protaphorura, and must therefore synonymize the former genus with the latter.

Key to the Genera of the Onychiurinae
1. Pseudocelli present 2
Pseudocelli absent * Pachytullbergia Bonet, 1947 (131)
2. Large species with furcula present and well developed 3
Smaller species; furcula if present very much reduced 4
3. Postantennal organ present; sense organ Ant. III with 4–5 papillae Homaloproctus Börner, 1909 (150)
Postantennal organ absent; sense organ Ant III with 14–15 papillae arranged in three rows Tetrodontophora Reuter, 1882 (880)
4. Pseudocelli with distinct chitinous borders; cuticle finely granulate; furcula present or absent 5
Pseudocelli without distinct chitinous borders; cuticle coarsely granulate; furcula always present Kalaphorura Absolon, 1901 (14)
5. Vesicles of postantennal organ arranged as two parallel rows, often more or less covered by secondary tubercles 6
Vesicles of postantennal organ generally simple, sometimes few in number, not arranged in parallel rows 11
6. Pseudocelli numbering at least 24, often more, and present on hind margin of head 7
Pseudocelli reduced in number (13–18) and absent from hind margin of head 10
7. Small species; postantennal organ with up to 30 vesicles 8
Very large species; postantennal organ with up to 90 vesicles 9
8. Sense organ Ant III with coarsely tuberculate capitate sense clubs ** Protaphorura Absolon, 1901 (14)
=Onychiuroides Bagnall, 1935 (76)
Sense organ Ant III with smooth capitate sense clubs Onychiurus Gervais, 1841 (1232) (484)
=Lipura Burmeister, 1838 (198)
Anurophorus Nicolet, 1841 (797)
(in part)
Adicranus Bourlet, 1843 (160)
(in part)
Augenius Gistel, 1848 (510)
Aphorura MacGillivray, 1893 (724)
Lophognathella Börner, 1908 (149)page 10
9. Postantennal organ with 30–38 vesicles; sense organ Ant III with elongated, roughened sense rods, elongated papillate sense clubs, and one or more truncated papillae Absolonia Börner, 1901 (138)
Postantennal organ with 70–90 vesicles; sense organ Ant III with lamellate sense clubs Spelaphorura Bagnall, 1948 (87)
10. Small species; postantennal organ with up to 24 vesicles; anterior pseudocelli of head outside antennal base area; lateral thoracic pseudocelli assent Paronychiurus Bagnall, 1948 (87)
Large species; postantennal organ with 100 or more vesicles arranged as an elongated mass; anterior pseudocelli of head within antennal base area; all thoracic pseudocelli absent Pseudonychiurus Bagnall, 1948 (87)
11. Postantennal organ simple, with few vesicles 12
Postantennal organ compound, with many irregular vesicles arranged as a rectangular mass Psyllaphorura Bagnall, 1948 (87)
12. Vesicles of postantennal organ simple, separated, 8–11 in number Hymenaphorura Bagnall, 1948 (87)
Vesicles of postantennal organ of varied form, 17–25 in number Heteraphorura Bagnall, 1948 (87)
Sub-Family * Hypogastrurinae Börner, 1906

* This sub-family name is adopted here pending the final decision of the International Commission on Zoological Nomenclature concerning the validity of the generic name Hypogastrura Bourlet, 1839. See Science, 1947, 106 (2673), p. 584.

Key to the Genera of the Hypogastrurinae
1. Postantennal organ present 2
Postantennal organ absent 17
2. Furcula present 3
Furcula absent 16
3. Postantennal organ simple, more or less elliptical, without well-defined peripheral lobes 4
Postantennal organ with either well-developed or rudimentary peripheral lobes 5
4. Anal spines present; three clavate tenent hairs to each foot Gomphiocephalus Carpenter, 1908 (225)
Anal spines absent; two clavate tenent hairs to each foot Choreutinula Paclt, 1944 (1216)
=Beckerellodes Salmon, 1945 (918)
Beckerella Axelson, 1912 (690)
5. Peripheral lobes of postantennal organ well developed 6
Peripheral lobes of postantennal organ poorly developed, indistinct 15
6. Cuticle very strongly granulate 7
Cuticle finely granulate or smooth 8
7. Unguiculus present well developed; anal spines, two, small Proxenyllodes Denis, 1926 (359)
Unguiculus rudimentary or absent; anal spines, three, on large papillae Triacanthella Schäffer, 1897 (934)
=Triacanthurus Willem, 1903 (1138)
8. Not more than four peripheral lobes to each postantennal organ 9
More than four peripheral lobes to each postantennal organ 14
9. With large eversible sac between antennal segments III and IV Ceratophysella Börner, 1932 (1203)
Without eversible sac 10page 11
10. Ocelli eight to each side 11
Ocelli less than eight to each side 12
11. Anal spines when present simple; either straight or curved, with or without papillae Hypogastrura Bourlet, 1839 (159)
=Podura Linné, 1758 (722) (in part)
Achorutes Templeton, 1835 (1055)
(in part)
Achoreutes Templeton, 1842 (1056)
(in part)
Rathumoutes Templeton, 1842 (1056)
(in part)
Achorutes Tullberg, 1872 (1074)
Podurhippus Megnin, 1878 (751)
Schoturus MacGillivray, 1893 (724)
Neohypogastrura Paclt, 1944 (825)
Neogastrura Stach, 1949 (1028)
* Agreniella Bagnall, 1949 (88)
* Lubbockiella Bagnall, 1949 (88)
Anal spines present and of unusual form, there being two stout spines arranged on a large common base, like a pair of pincers; each spine with a secondary smaller spine on its dorsal face Ancistracanthella Gisin, 1949 (509)
12. Anal spines present, two shorter than claw; ocelli, two to each side Xenyllogastrura Denis, 1932 (371)
Anal spines present, two longer than claw 13
13. Ocelli 2–5 to each side; pigmented species Schäfferia Absolon, 1900 (7)
=Octomma Willem, 1902 (1138, 1028)
Ocelli absent; pigment absent Spelaeogastrura Bonet, 1945 (128)
14. Ocelli present, two to each side; body pigment absent; unguiculus bristle-like, without lamella Mesachorutes Absolon, 1900 (7)
Ocelli absent; body pigment weak or absent; unguiculus with broad inner lamella Typhlogastrura Bonet, 1930 (115)
15. Ocelli eight to each side; unguiculus absent or reduced to small bristle only; pigmented species Schötella Schäffer, 1896, (933)
Ocelli two to each side; unguiculus present as long bristle; body pigment weak or absent Mesogastrura Bonet, 1930 (115)
16. Clavate tenent hairs present, usually three to each foot; ocelli absent Tafallia Bonet, 1946 (130)
Clavate tenent hairs absent Willemia Börner, 1901 (137)
17. Furcula present, but reduced 18
Furcula absent 19
18. Ocelli present, five or eight to each side; pigmented species Xenylla Tullberg, 1869 (1072)
Ocelli absent; pigment absent Acherontides Bonet, 1945 (128)
19. Ocelli present, five to each side; some body setae serrate; pigmented species Propexenylla Salmon, 1944 (917)
Ocelli absent; pigment absent; body setae smooth 20
20. Tenent hairs and anal spines present Acherontiellina Delamare-Deboutteville, 1948 (334)
Tenent hairs and anal spines absent Acherontiella Absolon, 1913 (21)

The name Hypogastrura is reverted to here pending the decision of the International Commission on Zoological Nomenclature concerning the case for its retention on the official list.

* In Bagnall's descriptions of these two genera I can find no characters of sufficient importance to warrant their retention as separate genera, and I am forced, therefore, for the present at least, to include them as synonyms only.

page 12
Sub-Family Neanurinae Börner, 1906
Tribe Brachystomellini nov.

* This genus was described in the Zool. Anz., 29, p. 72, for a species P. bogoyawlensky from the Persian Gulf, which I consider, from the original description is synonymic with Pseudanurida. Womersley (1939, Primitive Insects of South Australia, p. 315) referred to this under the name Pseudachorutoides. The spelling used by Becker, however, was Pseudachorutides.

Key to the Genera of the Brachystomellini
1. Mandibles present, with some apical teeth, but without molar area 8
2. Unguiculus present; ocelli six to each side; postantennal organ present, with four peripheral lobes; furcula present Microgastruro Stach, 1922 (1005)
Unguiculus absent 3
3. Postantennal organ present 4
Postantennal organ absent 5
4. Ocelli five to each side; anal spines present, six, on papillae Subantarctica Salmon, 1949 (925)
Ocelli eight to each side; anal spines absent Schoettellodes Becker, 1905 (1202)
5. Anal spines present 6
Anal spines absent; furcula present, very long and slender; antennae three times as long as head Pseudanurida Schött, 1901 (959)
=Neachorutes Womersley, 1933 (1167)
* Pseudachorutides Becker, 1905 (100)
Pseudachorutoides Womersley, 1931 (1181)
6. Furcula present; anal spines 2–7 in number, straight and without papillae Polyacanthella Schaeffer, 1897 (934)
=Oudemansia Schött, 1901 (959)
Conotelsa Denis, 1925 (354)
Friesea Denis, 1931 (368)
Furcula absent or greatly reduced 7
7. Anal spines four, needle-like, without papillae; furcula absent Colonavis Salmon, 1949 (925)
Anal spines up to five, evenly curved and on papillae; furcula greatly reduced or absent Friesea Dalla Torre, 1895 (280)
=Triaena Tullberg, 1871 (1073)
MacGillivraya Grote, 1894 (514)
Pseudotullbergia Schaeffer, 1897 (934)
Achorutoides Willem, 1901 (1135)
Triaenura Olfers, 1907 (805)
8. Furcula present 9
Furcula absent 17
9. Abds. V and VI separated, distinct 10
Abds. V–VI fused; ocelli seven to each side; mucro tapering to tip Gaucharia Jackson, 1927 (614)
10. Dens with setae only; unguiculus present or absent 11
Dens with spines as well as setae 21
11. Ocelli eight to each side; postantennal organ with up to seven peripheral separated lobes arranged as a star or rosette; furcula present; mucro tapering with lamella Brachystomella Agren, 1903 (40)
=Chondrachorutes Wahlgren, 1906 (1107)
Ocelli five or fewer to each side 12
12. Ocelli, two or five to each side 13
Ocelli absent 16
13. Unguiculus present, short, bristle-like; postantennal organ with three lobes; ocelli, two or five to each side; two small anal spines Xenyllodes Axelson, 1903 (55)
Unguiculus absent 14page 13
14. With three large anal spines on papillae; ocelli, five to each side Triondontella Stach, 1949 (1028)
With only two anal spines 15
15. Anal spines well developed, with or without papillae; mucro reduced, simple, pointed, without lobes; postantennal organ with 3–5 lobes; ocelli, five to each side Zealandella Salmon. 1942 (913)
Anal spines reduced to two large cuticular granules; mucro with two lobes; postantennal organ with four lobes; ocelli, five to each side Odontella Schaeffer, 1897 (934)
16. Postantennal organ present with 6–8 separated peripheral lobes Folsomiella Bonet, 1930 (115)
Postantennal organ absent Bonetella Stach, 1949 (1028)
17. Abds. V and VI separated, distinct 18
Abd. VI very small and more or less enclosed anteriorally and laterally by Abd. V; posterior borders of Abds. IV and V with four minute anal spines; ocelli, eight to each side Quatacanthella Salmon, 1945 (918)
18. The longer setae of the body and appendages clavate, the clavate portion divided into four lobes; ocelli; eight to each side Setanodosa Salmon, 1942 (913)
Setae not clavate, normal 19
19. Body rather stout; Ant IV with large apical trilobed papilla 20
Head and Thor. I very small with body swelling to relatively large size posteriorly; ocelli, five to each side; postantennal organ with four separated peripheral lobes Pseudontella Salmon, 1942 (913)
20. Ocelli, eight to each side; postantennal organ generally with four peripheral lobes, rarely 6–8 Salmonella Stach, 1949 (1028)
Ocelli, five to each side; postantennal organ with five peripheral lobes around central boss Odontellodes Stach, 1949 (1028)
21. Postantennal organ present 22
Postantennal organ absent; ocelli, eight to each side Subclavontella Stach, 1949 (1028)
22. Ocelli, eight to each side Australella Stach, 1949 (1028)
Ocelli, five to each side 23
23. Ant. IV with apical sensory swellings and complicated sense organs of rods, clubs, and sometimes sacs Clavontella Salmon, 1944 (917)
Ant IV without apical or other sense organs; legs and sides of head with conical spines Superodontella Stach, 1949 (1028)
Tribe Anuridini nov.
Key to the Genera of the Anuridini
1. Postantennal organ present 2
Postantennal organ absent 8
2. Postantennal organ circular or elliptical with 5–40 peripheral lobes 3
Postantennal organ with three contiguous lobes; one ocellus to each side; unguiculus absent; furcula reduced to simple fork-like structure Stachia Folsom, 1932 (466)
3. Maxilla head with toothed median shaft and two to three lateral subapical lobes either serrated or ciliated 4
Maxilla needle-like; postantennal organ with five to twelve peripheral lobes arranged as a rosette or 16 to 22 arranged as an ellipse; ocelli one to five to each side Micranurida Börner, 1901 (136)page 14
4. Mandible with single hook-like apical tooth and subapical lamella, ocelli absent, postantennal organ with eight to twenty peripheral lobes Anuridella Willem, 1906 (1142)
Mandible with several apical teeth 5
5. Furcula rudimentary, reduced to a pair of small tubercles; ocelli, five to each side Hypanurida Denis, 1931 (369)
Furcula absent 6
6. Ocelli five to each side Anurida Laboulbene, 1865 (653)
=Achorutes Guérin, 1838 (515)
Anoura Nicolet, 1847 (801)
Aphoroma Dalla Torre, 1895 (280)
Ocelli less than five to each side 7
7. Ocelli three to each side * Gastranurida Bagnall, 1949 (88)
Ocelli absent * Aphoromma MacGillivray, 1893 (724)
=Anurodes Bagnall, 1949 (88)
8. Mandible present, with some apical teeth; maxilla needle-like; furcula, unguiculus, and anal spines absent Paranura Axelson, 1902 (54)
=Börneria Axelson, 1902 (54)
Mandibles absent; ocelli, eight to each side; postantennal organ absent; Abd. VI narrow and tapering to a point dorsally 9
9. Furcula present Anuritelsa Womersley, 1939 (1181)
Furcula absent Meganurida Carpenter, 1935 (242)
Tribe Neanurini Börner, 1906

* With the establishment of Gastranurida by Bagnall for those Anurida-like species with three ocelli to each side, it becomes necessary to re-establish the genus Aphoromma MacGillivray for those species previously included within Anurida but without ocelli. From Bagnall's description of the genus Anurodes, it would appear that this genus is a synonym of Aphoromma —Genotype A. granaria (Nic.).

The sub-genus Lobella proposed by Börner in 1906 is, in my opinion, untenable, as the grounds of distinction given—the fusion or non-fusion of the latero-dorsal bosses on Abd. V—are not constant among the known species of Neanura.

Key to the Genera of lThe Neanurini
1. Mandibles present, each with two parallel toothed lamellae; Abd. VI bilobed Womersleya Denis, 1948 (400)
Mandibles absent 2
2. Head of maxilla without teeth or lamellae, lancet-like; unguiculus absent; furcula absent; sixth abdominal segment visible from above 3
Head of maxilla with both teeth and lamellae 7
3. Ocelli present 4
Ocelli absent 6
4. With both dorsal and lateral bosses and setae Neanura MacGillivray, 1893 (724)
=Achorutes Templeton, 1835 (1055)
Blax Koch, 1840 (633)
Anoura Gervais, 1843 (483)
Anura Nicolet, 1847 (801), Tullberg, 1869 (1072)
Biclavella Willem, 1902 (1138)
Lobella Börner, 1906 (147)
Without dorsal bosses or setae 5
5. Lateral bosses and setae present Gnatholonche Börner, 1906 (147)
Bosses absent except for a single ocular boss to each side of head; body very broad and flat Phylliomeria Delamare-Deboutteville, 1948 (331)
6. Abd. VI bilobed; head and body with very long simple setae; Abds. I–V fused Sericanura Carpenter, 1935 (242)
Abd. VI hidden below Abd. V; Abd. V truncate posteriorly; head and body with stout spines dorsally Echinanura Carpenter, 1935 (242)page 15
7. Sixth abdominal segment visible from above Protanura Börner, 1906 (147)
Sixth abdominal segment hidden beneath fifth Morulina Börner, 1906 (147)
Tribe Pseudachorutini Börner, 1906

* The first species belonging to the genus Holacanthella was described by Lubbock in 1899, along with two other species from Tasmania, all of which he placed in the genus Anoura. As the name Anoura was a homonym, Börner, in 1906, proposed the new name Holacanthella for the New Zealand species ana Acanthanura for the two Tasmanian species. Later, it was suggested mat these "spiney" species and the more usual flattened, plain, species described under the name Ceratrimeria Börner were apparently the same generically. This view was upheld by Womersley (Jour, Linn. Soc., XI, 1937), and all species with paratergal swellings or prominent pleural areas were lumped together under the generic name Ceratrimeria. In 1925, Carpenter erected a new genus Platanurida for a Ceratrimeria-like species; and Womersley, in 1937, erected a genus Tasmanuro for another closely related form from. Tasmania. In 1941, I included Platanurida in the genus Ceratrimeria. Later, in 1942, I recognized that the genus Ceratrimeria, as then visualized, contained in New Zealand two clearly defined groups, which I designated the spinosa and lata groups respectively. From further careful study of these two groups, I am convinced that two genera are involved, and that Börner's earlier diagnosis, in which the "spiney" forms were placed in the genera Holacanthella and Acanthanura, was correct. There seems no doubt whatever that the species belonging to the genera Holacanthella and Acanthanura were incorrectly included in the genus Ceratrimeria, as, in addition to the differences in body structure between them and the latter genus, there also is the complete absence of the furcula. The two genera are confined to the southern regions, Holacanthella being peculiar to New Zealand and Acanthanura to Tasmania, as distinct from Ceratrimeria, which is much more cosmopolitan in distribution. Stach differentiates the genus Womersleymeria from Acanthanura principally on the form of the postantennal organ, which is a cluster instead of an ellipse as in Acanthanura. I do not consider this difference of sufficient weight in view of the similarity of the paratergal structures which are the principal feature of these genera.

* The sub-genus Sphragiphora Houlbert, 1924. This sub-genus was proposed by Houlbert ("Thysanoures, Dermapteres, et Orthopteres de France et de la Faune européene," p. 67) for those species belonging to the genus Pseudachorutes Tullb., in which the postantennal organ was present, while those species without a postantennal organ were left in the genus Pseudachorutes. However, this separation proposed by Houlbert must be invalid, as P. subcrassus Tullb., the type species of the genus Pseudachorutes has a well-developed postantennal organ. The sub-genus Sphragiphora Houlbert falls, therefore, as a synonym of the genus Pseudachorutes Tullberg, 1871.

Key to the Genera of the Pseudachorutini
1. Postantennal organ present 2
Postantennal organ absent 15
2. Paratergal areas and body segments dorsally with many long finger-like or short spine-like processes of the cuticle 3
Without such finger-like or spine-like processes 4
3. Paratergal areas very strongly developed, greatly swollen and prolonged laterally into strong elongated finger-like processes, there being one to each pleural area or body segment * Acanthanura Börner, 1906 (147)
=Anoura Lubbock, 1899 (715) (in part)
Ceratrimeria Börner, 1906 (147) (in part)
* Womersleymeria Stach, 1949 (1029)
Paratergal areas well developed but not so swollen and not prolonged into finger-like processes; instead, covered with numerous short, blunt, spine-like processes, of which there are several to each pleural area or body segment * Holacanthella Börner, 1906 (147)
=Anoura Lubbock, 1899 (715) (in part)
Ceratrimeria Börner, 1906 (147) (in part)
4. Postantennal organ with the lobes arranged in either a circle or ellipse or as a cross 5
Postantennal organ with the lobes arranged in a cluster 12
5. Body segments with distinct paratergal areas that are often greatly swollen or enlarged 6
Body segments without prominent paratergal areas, but with indications of such 11
6. Abd. VI completely hidden below Abd. V, not visible from above 7
Abd. VI not completely hidden, partly visible from above 9page 16
7. Ocelli, eight to each side 8
Ocelli, five to each side; body noticeably flattened, with distinct paratergal areas; postantennal organ with 9–13 lobes in a rosette; furcula greatly reduced to two small knobs Platanurida Carpenter, 1925 (237)
8. Furcula present, well developed; paratergal areas well developed; postantennal organ with 12–28 lobes in an ellipse Ceratrimeria Börner, 1906 (147)
=Schoetella Schaeffer, 1897 (933)
Furcula absent; paratergal areas well developed and rounded; postantennal organ with up to 30 lobes in an ellipse; body densely clothed with fine setae Meganura Handschin, 1942 (563)
9. Posterior margin of Abd. V straight 10
Posterior margin of Abd. V emarginated and surrounding the median portion of Abd. VI visible from above; furcula present but short Megachorutes Handschin, 1942 (563)
10. Furcula well developed; paratergal areas distinct; body rather plump; postantennal organ with 8–20 lobes in a rosette or ellipse Zealandmeria Stach, 1949 (1029)
Furcula reduced, stump-like; body broad and flat, with prominent lateral paratergites; postantennal organ with four lobes arranged as a cross Tasmanura Womersley, 1937 (1179)
11. Maxilla with distinct head and two lamellae; ocelli, eight to each side; postantennal organ with 15–20 lobes in an ellipse; mucro usually wedge-like Pseudachorudina Stach, 1949 (1029)
Maxilla without distinct head or lamellae; ocelli, 5–8 to each side; postantennal organ with 3–20 lobes arranged as a circle or an ellipse; mucro generally spoon-like Pseudachorutes Tullberg, 1871 (1073)
=Gnathocephalus MacGillivray, 1893 (724)
Brachysius MacGillivray, 1893 (724)
* Sphragiphora Houlbert, 1924 (597)
12. Abd. VI partly visible from above 13
Abd. VI completely hidden below Abd. V and not visible from above; ocelli, six to each side; postantennal organ with about 80 lobes; furcula short Cryptotrimeria Stach, 1949 (1029)
13. Ocelli, eight to each side; postantennal organ with 17–40 lobes Aethiopella Handschin, 1942 (563)
Ocelli, fewer than eight to each side 14
14. Furcula well developed; ocelli, five to each side Americotrimeria Stach, 1949 (1029)
Furcula reduced, with elongated mucro; ocelli, 5–6 to each side Neotropiella Handschin, 1942 (563)
15. Ocelli, eight to each side 16
Ocelli, fewer than eight to each side 18
16. Furcula well developed; posterior margin of Abd. V straight 17
Furcula reduced, very short; dens wart-like; mucro hook-like and not separated from dens; body usually flattened and with paratergal areas strongly marked; posterior border of Abd. V emarginated Linnaniemia Philiptschenko, 1926 (855)page 17
17. Mucro boat-like; mandible with two apical teeth Pseudachorutella Stach, 1949 (1029)
Mucro long, slender; mandible with eight apical teeth Montachorutes Stach, 1949 (1029)
18. Furcula present 19
Furcula absent; ocelli, six to each side; Abd. VI almost hidden below Abd. V Brosilimeria Stach, 1949 (1029)
19. Ocelli, five to each side; mandible with not more than four apical teeth Arlesia Handschin, 1942 (563)
Ocelli, seven to each side; mandible with 25–30 teeth at apex Handschinia Stach, 1949 (1029)