486 FAMILY XII. TEICHOPTERYGID^. 



KEY TO INDIANA GENEBA OF TRICHOPTERYGID^. 



a. Elytra entire. 



&. Thorax widest at base. 



c. Pygidium invisible ; form oval, very convex ; color dark. 



I. N0S8ID1UM. 



cc. Pygidium visible beyond the elytra; hind angles of thorax not 



elongate ; form elongate ; color pale. 



6&. Thorax widest before the base. 



d. Pygidium visible beyond the elytra. 

 eld. Pygidium invisible. 



(la. Elytra truncate. 



c. Antennse very short, 9-jointed ; eyes wanting ; 



elytra. 



v(;. Antennae elongate, 11-jointed. 

 /. Thorax widest at the base. 

 g. Abdomen with seven ventral segments. Pteryx. 



og. Abdomen with six ventral segments. 

 , h. Hind coxos very widely separated; mesosternum scarcely cari- 



nate; color pale. Ptineixodes. 



Ml. Hind coxte moderately separated ; mesosternum distinctly cari- 

 nate. IV. Tktchoptebyx. 



//. Thorax widest before the base. 



i. Elytra long ; mesosternum carinate ; color dark. "\'. Smickus. 

 U. Elytra short; mesosternum not carinate. 



j. Body opaque ; abdomen moderate ; iiind coxte with plates. 



Nephanes. 

 jj. P.ody translucent ; abdomen very long ; color pale. 



VI. PTINELI.A. 



I. NossiDiuM Erichs. 1845. (Gr., "nest + formed.") 

 Small oval, convex species having joints 1 and 2 of antennae very 

 large, 3-8 slender, 9-11 much thickened ; abdomen with seven seg- 

 ments, entirely covered by elytra : metasternum not reaching the 

 sides of the body. One of the two known species occurs in the 

 State. 

 934 (2914). NossiDiUM amekicanum Jlots.. Bull. Mosc, 41, lS(i8. 191. 



Oblong-oval, very convex. Head and thorax 

 piceous, strongly shining; elytra reddish-brown, 

 rather thickly clothed with long yellowish hairs ; 

 legs and antenna^ yellow. Thorax more than 

 twice as wide as long, hind angles rectangular; 

 sides rounded, distinctly margined, surface very 

 finely and sparsely punctured. ]<"lytra not wider 

 than thurnx, surface with rather deep, rugose 

 punctures in sinuate transverse rows; tips broad, 

 much rounded. Length 1 mm. (Fig. 173.) 



Monroe rounty; frc(iuont. iMay 13-June 

 9. Taken by sifting del)ris of beech stump. 

 Fig. 173. X 34. (Original.) Probably occui-s throughout the State. 



