138 MEMOIRS ON THE COLEOPTERA 



elytra, black, moderately and very gradually incrassate, the first three 

 joints long, equal in length, the fourth slightly elongate, five to nine 

 increasing but slightly in size, mutually similar, as long as wide, the tenth 

 wider than long and abruptly a little wider, though of the same length, 

 as the ninth, the last gradually acutely pointed, barely as long as the two 

 preceding; prothorax small, a fifth wider than long, widest before the 

 middle, where the sides are broadly rounded, thence moderately converg- 

 ing and straight to the distinct basal angles, convex, the median line 

 very finely and obsoletely impressed, broadly subdepressed basally, 

 where there is a rather deep rounded ante-scutellar pit; elytra large, 

 moderately transverse, parallel, the sides very feebly rounding and sub- 

 inflated posteriorly, at base one-half wider, the suture nearly one-half 

 longer, than the prothorax, the apices truncate externally; abdomen long, 

 slightly narrower than the elytra, parallel, the fifth tergite but little 

 longer than the fourth; middle coxae contiguous medially through a 

 much shorter distance than usual, the metasternal projection very large, 

 nearly as long as wide and sharply angulate. Length 3.5 mm.; width 

 0.75 mm. Mexico (Saltillo, State of Coahuila), Wickham. 



This distinct species does not appear to have been included with 

 the material worked up by Dr. Sharp for the "Biologia." 



Hydrosmecta Thorns. 



This genus, like many others founded upon European stem forms, 

 is composite and will necessitate the formation of numerous sub- 

 genera; the three following species are passably conformable to 

 the generic type, though including two types of antennal structure: 



Hydrosmecta odiosica n. sp. Very slender, but feebly convex, per- 

 fectly parallel, dull in lustre, the fine sculpture strong throughout, 

 the punctures fine, close-set and asperulate, the abdomen but little more 

 shining; vestiture s ort and abundant, grayish; color piceous-black 

 throughout, the abdomen moderately pale at apex, the legs piceous- 

 brown; head subquadrate, very nearly as wide as the prothorax, very little 

 wider than long, the eyes well developed, at barely their own length 

 from the base, the tempora parallel, subequally prominent or just visibly 

 swollen basally; antennae long, very slender, scarcely at all incrassate, 

 blackish throughout, extending to about the tips of the elytra, all the 

 joints much longer than wide, the second distinctly longer than the third, 

 the tenth nearly one-half longer than wide, eleventh long, cylindric, 

 almost as long as the two preceding; prothorax but very slightly wider 

 than long, slightly widest at apex, the sides thence feebly converging 

 posteriorly and only slightly arcuate, the median line distinctly impressed 

 from just before the middle to the base; elytra parallel, fully as long as 

 wide or apparently a little longer, equal in width to the widest part of 

 the prothorax, the suture about a third longer; abdomen lone, barely 

 visibly narrower than the elytra, parallel, with perfectly straight sides, 

 the first three tergites increasing slightly in length, the first impression 



