292 FAMILY IX. SCYDMiEXIDiE. 



of the eye coarser. In general form and size they resemble the 

 Pselaphida?. but the elytra are always entire and the tarsi 5- instead 

 of 3- jointed. 



In addition to the characters mentioned, they have the maxillary 

 palpi long, the last joint very small; antennas inserted upon the 

 front, at the inner margin of the eyes, gradually thickened or slight- 

 ly club-shaped toward apex; prosternum not visible between the 

 coxge; elytra convex, covering the abdomen, the latter with six free 

 ventral segments ; front coxae conical, prominent, contiguous; middle 

 ones somewhat distant ; hind ones small, conical or transverse, often 

 widely separated ; tarsi 5- jointed, claws simple. Nearly 700 species 

 are known, about 175 of which are from the United States. These 

 are treated in the following papers : 



LeConte. — "Synopsis of the Scydmamida? of the United States," 

 in Proc. Phil. Acad. Nat. Sci.. YI. 1852. 149-157, 



Casey. — -"Revision of the Scydmamida? of the United States." 

 in Ann. N. Y. Acad. Sci., IX, 1897, 351-548. 



In his Revision, Casey divided the family into two subfamilies, 

 only one of which, the Scydmaminse, is represented in Indiana, The 

 principal distinguishing characters given of this subfamily are as 

 follows: Antennas generally distinctly clavate. usually elbowed, 

 but with the basal joint short or moderate in length; hind coxae 

 transverse or transversely oval ; metasternum large ; abdomen short ; 

 elytra never striate or with rows of punctures. The subfamily is 

 separated into ten tribes, four of which are known to be repre- 

 sented in the State, while two others may be. 



KEY TO INDIANA TRIBES OF SCYDMiENINiE. 



a. Fourth joint of maxillary palpi awl-shaped, finely aciculate and oblique; 

 antennae widely separated at base. 

 It. Prosternum short and deeply sinuate before the coxae; neck short and 

 abruptly constricted. 

 c. Neck narrow ; eyes in front of middle of head ; scutellum wanting. 



Tribe I. Euconnini. p. 293. 

 cc. Neck wide; eyes basal or sub-basal in position; scutellum always 

 present. Tribe II. Scydm^enini, p. 301. 



hb. Prosternum rather long and pubescent before the coxae ; thorax ob- 

 oral ; length less than .8 of a millimetre. 



Tribe III. Opresini, p. 302. 

 ar/. Fourth joint of maxillary palpi obtuse, never awl-shaped, obscure or 

 fused rigidly to the apex of third, sometimes wanting. 

 (1. Hind coxae transverse, extending to the sides of the body; antenna? 

 widely separated at base. 



