[95] 



NORTH AMERICAN COLEOPTERA. 251 



eyes for the reception of the antennas when in repose; epistoina very small, 

 deflexed, divided by a fine distinct, straight suture; labrum small, transverse, 

 vertical, detached from and covered by the epistoma; antennae inserted under 

 the sides of the front, immediately before the eyes, 11-jointed, base thick, 

 gradually diminishing in thickness to the sixth joint, seven to nine very small, 

 tenth wider, small, transverse, eleventh widest, longer than wide, ovoidal, 

 maxillary palpi small, last joint slightly longer than wide, ovoidal, pointed, 

 slightly compressed. Prosternum well developed, transversely truncate an- 

 teriorly, widely separating the anterior coxa?; process transversely truncate at 

 apex, on the same level and in contact with the anterior edge of the mesos- 

 ternum; the latter extremely short, strongly transverse, very broadly and 

 feebly emavginate anteriorly; metasternum large, long; episternum narrow, 

 elongate, obliquely truncate anteriorly, widest and angulate interiorly near 

 the apex; metasternum slightly excavated at the side anteriorly for the recep- 

 tion of the tips of the intermediate femora, the excavatiou extending very 

 deeply and obliquely into the base of the elytrat hypomera. Anterior coxa? 

 very small, transverse, attenuate laterally, open behiud, widely separated; 

 trochanters large; middle coxa? not at all prominent, transversely oval, very 

 widely separated; trochanters large; posterior coxae strongly transverse, at- 

 taining the metasternal episterna, short, distinctly separated. Ventral seg- 

 ments five; three basal not distinctly connate; first four uniformly and grad- 

 ually decreasing in length; fifth as long as the two preceding together; first 

 segment deeply and transversely excavated at base for the reception of the 

 posterior femora. Prothorax short, broad; sides with an acute edge; infiexed 

 sides divided from the prosternum by a very distinct suture; prosternum lat- 

 erally and infiexed sides deeply and transversely excavated for reception of 

 the anterior femora; pronotum excavated laterally at apex for reception of 

 antennal club. Scutellum small, triangular. Elytra convex, covering the en- 

 tire abdomen; hypomera distinct, extending only for two-fifths the length 

 from the base, devoid of hypopleime. Legs short, rather slender; femora not 

 very robust, excavated along the lower edge for reception of the tibiaa; tbe 

 latter simple, rather slender, not grooved, having a line of short, very fine, 

 densely placed cilia along the outer edge; tarsi free, rather short, five-jointed 

 joints simple; first of the anterior as long as the next two together; two to 

 four very small; fifth as long as the three preceding together; claws divergent, 

 small, simple, slender. 



This genus is very remarkable in antennal structure, in 

 its excavated pronotum and many other characters. The 

 single representative almost exactly resembles a minute 

 Scymnus in external form. 



The median portions of the three sterna form a continu- 

 ous surface from the head to the posterior coxae, the meso- 



