494 Coleopterological Notices, VII. 



It is almost certain that the Scydmsenus ovithorax of Brendel^ 

 forms another genus in this tribe ; if this be not the case, how- 

 ever, there is no linown representative west of the Missouri River. 



OPRESUS n. gen. 



The species of this genus are the most minute of the Scydmse- 

 nidae, and could only be compared with Ptilium of the Tricho- 

 pterygidse in point of size. They are probably numerous, but only 

 three or four are known at present. The body is narrowly sub- 

 oval, feebly ventriculate, rather strongly convex, and clothed with 

 very short and rather sparse pubescence. The head is well de- 

 veloped, borne on a stout but deeply constricted and exposed 

 neck, and is but feebly inclined downward, the eyes median and 

 generally rather well developed, the antennae of the usual type in 

 neighboring tribes of the Scydmsenidse subulipalpi, the three 

 outer joints forming a distinct club. Front between the antennal 

 cavities narrow, nearly vertical and somewhat prominent ; labrum 

 transverse,truncate, the mandibles rather small, circularly rounded 

 externally. Prothorax obovulate, the subbasal markings fine, 

 consisting of two minute united median foveas and another near 

 each basal angle. Prosternum before the coxae rather long and 

 finely puberulent as in the other genera of the tribe. Scutellum, 

 completely wanting and covered by the pronotum. Elytra oval,, 

 somewhat individually rounded at apex, the dorsal pygidium 

 exposed at tip and broadlj^ rounded. 



The middle coxae are contiguous, the posterior very narrowly 

 separated, the narrow process of the metasternum between them 

 deeply and finely cleft as in Scydmaenini, extending virtually to- 

 the sides of the body. First ventral segment longer than the 

 next, the last two moderately elongate. Legs very short and 

 rather stout, the hind tarsi short, with the four basal joints equal;, 

 claws short and strongly arcuate. Secondary sexual characters 

 appear to be wanting. 



The three species known to me may be separated as follows : — 



Elytra each with two minute basal impressions, the vestiture finer and closely- 

 decumbent, generally intermingled on the elytra with remote erect setse 

 which are short and inconspicuous ; body narrower, more punctulate 

 anteriorly. 

 Elytra less inflated, parallel and not more than % wider than the prothorax ;. 

 eyes rattier smaller 1 misellus- 



