292 FAiriLY IX. — SCYDlLi;XID.«. 



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

 Pselaphidff. Init 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; antennfe 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 

 coxaa; elytra convex, covering the abd.omen, the latter with six free 

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

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

 ^yidely 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 Scydma?nidic of the United States," 

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



Casey. — "Revision of the Scydmsenidae 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 Scydmseninaj, is represented in Indiana. The 

 principal distinguishing characters given of this subfamily are as 

 follows: Antennae generally distinctly clavate, usually elbowed, 

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

 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 knoMTi to be repre- 

 sented in the State, while two others may be. 



KEY TO INDIANA TRIBES OF SCYmr^NIN.E. 



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

 antennas widely separated at base. 

 6. Prosternum short aud deeply sinuate before the eox:e: neck short and 

 abruptly constricted, 

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



Tribe I. Euconnini, p. 293. 



cr. Nei/k wide; eyes basal or sub-basal in position; scutellum ahvays 



present. Tribe II. Scyhm.enini, p. 301. 



hh. Prosternum ratlier long aud pubescent before the e(ix:e: thorax ob- 



oval ; length less than .S of a millimetre. 



Tribe III. Opresini, p. 302. 

 aa. Fourth joint of maxillary palpi obtuse, uever awl-shaped, obscure or 

 fused rigidly to the apex of third, sometimes wanting. 

 (1. Hind ooxne transverse, extending to the sides of the body; antennae 

 widely separated at base. 



