44 BULLETIN 168, UNITED STATES NATIONAL MUSEUM 



Dentes longer than manubrium, slender and tapering, with a 

 great many fine transverse dorsal crenulations. Mucro bi- 

 dentate, not lamellate. Postantennal organ usually notched 

 or constricted at the middle. Unguiculus without a pair 

 of inner lamellae. Integument smooth, not tuberculate or 

 reticulate 13 



5. Mucrones lamellate. Dentes with 15 to 20 coarse dorsal folds. 



Unguiculus with a pair of inner lamellae. Tenent hairs one 

 or two. Postantennal organ usually notched or constricted 

 at the middle. Eyes 16. Genital and anal segments usually 



ankylosed 6 



Mucrones not lamellate. Dentes with rarely more than 10 

 dorsal folds. Unguiculus without a pair of inner lamellae. 

 Tenent hairs present or absent. Postantennal organ with 

 or without a notch. Furcula not attaining the ventral tube 7 



6. Furcula extending not quite to the ventral tube. Integument 



reticulate. Antennae not telescopic. Dark purple titusi (p. 49) 



Furcula attaining the ventral tube. Integument not reticulate. 



Antennae telescopic. Dark purple longispina (p. 50) 



7. Dens with a lateral subapical bladderlike appendage. Manu- 



brium with three or many ventral subapical setae. Tibio- 

 tarsus not subsegmented. One tenent hair. Postantennal 

 organ with an anterior notch (sometimes absent). Integu- 

 ment more or less tuberculate or reticulate 8 



Dens without a bladderlike appendage. Manubrium with one 

 pair or four pairs of ventral subapical setae. Integument 

 not tuberculate or reticulate (except in obsoleta) 9 



8. Mucro tridentate. Dens with about 8 to 10 dorsal folds. 



Manubrium slightly longer than dentes, with three ventral 



subapical setae. Dark blue vesiculata (p. 57) 



Mucro quadridentate. Dens with about 8 dorsal folds. Manu- 

 brium slightly shorter than dentes, or subequal to them, 

 with many ventral subapical setae. Dark blue bulbosa (p. 58) 



9. Dentes subcylindrical or swollen, rounded apically 10 



Dentes not rounded apically 11 



10. Manubrium longer than dentes. Tenent hairs one or two. 



Integument not reticulate. Dark purple brevipenna (p. 56) 



Manubrium shorter than dentes. Tenent hairs absent. In- 

 tegument reticulate. Dark violet obsoleta (p. 56) 



11. Eyes present. Manubrium with one pair of ventral subapical 



setae 12 



Eyes absent. Manubrium with four pairs of ventral subapical 



setae. One tenent hair. White, with gray or black mottlings.frisoni (p. 55) 



12. Eyes 16. Tenent hairs one, two, or none. Dens typically with 



five or six dorsal folds. Genital and anal segments not 



ankylosed. Anus caudal. Grayish or bluish minuta (p. 51) 



Eyes 10 (sometimes 8) . Tenent hairs absent. Dens with 8 to 10 

 dorsal folds. Genital and anal segments ankylosed occa- 

 sionally sepulcralis (p. 54) 



13. Furcula not attaining the ventral tube. Manubrium with one 



pair or three pairs of ventral subapical setae 14 



Furcula attaining the ventral tube. Manubrium with two 

 pairs of ventral subapical setae. Genital and anal segments 

 not ankylosed. One tenent hair. Bluish or greenish immersa (p. 63) 



