AMERICAN COLEOPTERA, 47 



SEPIDUL.UIVI, 11. g. (Hydrophilidae.) 

 Body small ovate convex, without lustre, prothorax greatly pro- 

 duced in front over the head, divided by obtuse elevated lines into 

 large cells; elytra costate, costas separated by two distinct rows of 

 quadrate punctures. Head flat, densely punctured, occiput convex 

 and feebly channelled ; labruui short transverse, feebly rounded in 

 front, mandibles small, not prominent; eyes lateral, convex, partially 

 divided by the canthus, not very finely granulated; palpi short, last 

 joint nearly conical. Antennae as long as the head, 9-jointed ; 1st 

 joint about two-fifths of the whole length, elongate triangular, outer 

 edge subsinuate, inner edge angulated beyond the middle; 2d joint 

 nearly as wide as the widest part of the 1st joint, rather wider than 

 long, 3—5 smaller, nearly equal in length, but gradually a little nar- 

 rower, 6th transverse, triangular, inner angle acute, 7th to 9th larger, 

 forming a loose club, as long as the other joints (except the scape) 

 united; the 8th joint is wider, and the 9th longer than the others, the 

 latter obtusely rounded at tip. Prothorax produced over the head 

 into an obtuse lobe; sides dilated and rounded in front, narrowed 

 towards the base; disc uneven, with large impressions and obtusely 

 elevated lines, the most conspicuous being a large media'i rhomboidal 

 impression, extending almost from tip to base. Elytra wider than 

 prothorax, gradually wider behind, and obtusely rounded; suture, 

 margin and three costoe elevated, separated by two rows of quadat.; 

 punctures; between the outer costa and the margin is a large tuber- 

 cle about one-third from the base; there is also a broad oblique trans- 

 verse impression behind the base, which interrupts the 2d costa. 

 Prosternum very short in front of the coxae which are transverse and 

 contiguous; middle and hind coxte also contiguous; legs roughly and 

 densely punctured; tibiae moderately slender, feebly d'ilated,'^without 

 spurs; tarsi short (hardly one-third the length of the tibise), appar- 

 ently 4-joiated, claws small. 



The abdomen is deeply withdrawn in the cavity of the elytra; it is 

 fiat, and 1 can see but four ventral segments, the last is rounded at 

 tip, and vaguely impressed each side; there may, however, be five 

 segments, the 1st being invisible on account of the prominence of the 

 nietasternum and the contraction of the abdomen. 



The genus is named in allusion to the resemblance in form of the 

 prothorax to that of Sepidium. The characters are altogether anoma- 

 lous, but seem to resemble those of H^drophiUdae. rather than any 

 other family, approaching more nearly perhaps to OchthrUus. 



