Key to the Tribes of Neotropical Pselaphidae 



At present there are twenty-two tribes of Pselaphidae. In the present 

 paper two tribes (Euplectini and Trichonychini) are united. The Western 

 Hemisphere is represented by seventeen tribes. Four tribes (Dimerini, Mirini, 

 Cyathigerini and Schistodactylini) have no known American species. Four 

 tribes (Jubinini, Metopiini, Arhytodini and Attapsenini) are exclusively Amer- 

 ican; some tribes are poorly represented in the Western Hemisphere (Faronini, 

 Pyxidicerini, Batrisini, Pselaphini, Ctenistini, Hybocephalini and the sub- 

 family Clavigerinae) . These facts of distribution are taken advantage of in 

 the key which follows. 



This tribal key (Plates VI and VII), and all other keys in the present 

 study, are artificial in the sense that isolation of specimens is the goal, without 

 reference to evolutionary order. Consequently key characters of little phylo- 

 genetic weight may be employed, if by so doing tribes, or parts of tribes, can 

 be separated effectively. Again, this and the keys which follow relate spe- 

 cifically to the Neotropical Region (roughly the Americas south of the Tropic 

 of Cancer, and their associated island groups, to central Argentina) and should 

 not be expected to apply elsewhere. 



All seventeen tribes of the Americas are known from this region, and 

 their neotropical components may be separated as follows: 



Antennae of not more than three segments (PI. VI, 5) 



CLAVIGERINI 



(p. 350) 



Antennae of more than three segments (PI. VI, 6, 7) 2 



Tarsi with the second segment bilobed, the third segment cylindrical 

 and inserted between the lobes of the second; known only from 



South America (PI. VI, 3) ARHYTODINI 



(p. 343) 

 Tarsi with the second segment large or small, cylindrical, obconical, 



compressed or flattened but never bilobed 3 



Tarsi with the first two segments small and the third segment rela- 

 tively very large (PI. VI, 1 ) 4 



Tarsi with the first segment small and the last two segments rela- 

 tively very large (PI. VI, 2) 6 



Antennae of nine segments PYXIDICERINI 



(p. 37) 



Antennae of eleven segments 5 



(31) 



