AMERICAN COLEOPTERA. 255 



eyes. The prothorax and elytra are famished with longitudinal 

 costae, but the antennae, palpi, coxae, and terminal spine of the front 

 tibiae are as in Bothrideres 



Mychocerus Er. — Very small insects, which in external structure 

 have a general resemblance to Cerylon, but with the head so deeply re- 

 tracted into the prothorax, that the genus cannot be properly referred 

 to the same tribe, but must rather be reckoned as belonging to a sepa- 

 rate tribe of the same family, DERMESTlDiE. 



The clypeus is separated from the front by an evident suture; the 

 mandibles, palpi and labrum very short; the first two joints of the an- 

 tenna3 are thick, the 10th forms* a rounded club, received in a deep 

 fovea of the prothorax ; the latter is transverse, and shaped almost as 

 in the Anthreni; scutellum very small. Elytra covering all the dor- 

 sal segments. Under surface flat, with broad sterna, and therefore all 

 the coxae widely separated ; the prosternum separated from the lateral 

 depressed parts by a longitudinal carina, prolonged in front so as to 

 cover the mouth; first ventral segment as large as the other four to- 

 gether; tarsi slender 4-jointed. 



M. [depressus.^=3/M?'»Mcin<scfejor. Lee. Proc. Acad. Nat. Sc. 1866, 376.] Length 

 i line. Elliptical, slightly convex above, ferruginous, with yellow legs; under 

 a high lens the upper and under surface appear very finely punctured, and cov- 

 ered with fine pubescence. Prothorax transverse, twice as wide as long, with ob- 

 tuse front angles, upon which the antennal foveee are situated; the hind mar- 

 gin forms an obtuse angle at the middle, from which to the sides it is feebly 

 emarginate, the hind angles are acute, the sides converge obliquely in front, 

 flat, not deflexed, very finely margined, somewhat impressed near the hind 

 margin. Elytra very distinctly puncta'te-striate, in front as wide as the pro- 

 thorax, and closely affixed to it, behind rounded. — South Carolina. 



[I have been thus particular in translating the whole of Dr. Zim- 

 mermann's description, because on renewed examination of the speci- 

 mens I find that they differ from Murmidius generically by the anten- 

 nal foveas being iqwn the anterior angle of the prothorax extending 

 below, instead of above them as in Murmidius, in which they occupy 

 the dorsal surface just by the angle. Nevertheless, in comparing the 

 two species before me which represent the two genera, I cannot but be 

 convinced that they are closely allied, and that their affinities are rather 

 with Histeridae than Ceri/lou; nor in fact do I perceive any essential 

 generic distinction, apart from the one above mentioned and minor dif- 

 ferences in the antennae, except that the prosternal strife are more dis- 

 tant, and the anterior lobe less developed in Mychocerus than in Mur- 



* According to Erichson's description ; I have not been able to draw out the 

 antennae so as to count the number of joints. 



