78 THOS. L. CASEY. 



NARTHECmS Lee. 



Mandibles bidentate at the tip; ninth and tenth joints of antennae flattened; 

 eleventh elongated, not flattened, fusiform and acuminate at tip; second joint of 

 labial palpi enlarged and compressed : third joint elongated and fusiform. Last 

 joint of maxillary palpi elongated, slightly bent and prolonged in a narrow sub- 

 cylindrical process. Eyes on side of head, very flat and nearly circular; side pro- 

 cesses on under surface of head, resembling the jugular pieces of the Passandrinae, 

 feebly developed. 



We have but one species. 



1. N, graiKliceps Lee — Body elongated, cylindrical, deep blackish casta- 

 neous. Head slightly larger than the prothorax which is plainly margined ; punc- 

 tuation fine; middle of front projected forward into a short horn-like process; 

 upper surface provided with two lateral elevated ridges and one median furrow, 

 none of which attain the posterior margin ; there are also two small but very dis- 

 tinct anterior, lateral ridges which converge toward the horn-like process. Man- 

 dibles very large, evenly arcuate, and dentate internally. Eyes small, flat and 

 more visible from above than below, rather finely granulated. Antennae slightly 

 longer than head, enlarged toward the tip. Prothorax narrower posteriorly ; 

 sides nearly continuous with those of head, punctures finer and closer than on 

 head ; anterior angles not pronounced ; posterior angles acute. Elytra entire, a 

 little longer than the head and prothorax together, and almost imperceptibly wider 

 than the latter ; sides parallel ; evenly rounded behind; not punctured, but bav- 

 in"' faint longitudinal ridges. Scutellum evenly rounded behind. Fifth joint of 

 tarsi ornamented with ridges or striae. 



Plate IV, Fig. 13, and Plate V, Fig. 1. 



This curious species is of such excessive rarity that as far as my 

 knowledge extends, only three specimens are known in the collections of 

 the United States ; one a mutilated male in the cabinet of Dr. LeConte 

 from Pennsylvania, another in a private collection in Cincinnati, and the 

 third, a perfect specimen in that of Dr. Horn. The descriptions and 

 figures have been taken from the hitter, which was obtained in Nevada. 



PEDIACUS Schuck. 



Mentum short, strongly emarginate, with the interior angles acute. Ligula 

 bilobed anteriorly. Inner lobe of jnaxilla ciliated at its extremity. Last joint 

 of maxillarj' palpi acuminate, that of the labial palpi oval. Labruni rounded in 

 front. Head triangular, joined to prothorax by a short and very broad neck. Eyes 

 moderate in size and very convex, situated at the posterior angles of the head. 

 Antennae short and robust; last three joints suddenly enlarged, forming a loose 

 club. Prothorax sub-quadrate, not margined; sides serrulate, or undulated. Ely- 

 tra depressed, covering entire abdomen, and evenh' rounded behind. Tarsi hetero- 

 merous in the male, and pentamerous in the female: first joint very small. Body 

 elongated and very depressed. 



Our species are two in number, and may be distinguished as follows : 



Sides of prothorax arcuate and feebly undulated : punctuation extremely dense. 



1. fllSCllS. 

 Sides of prothorax nearly straight, and acutely, though rather feebly serrulate. 



2. (lepressiis. 



