io6 MEMOIRS ON THE COLEOPTERA 



verse, parallel, fully as wide as the prothorax, the eyes feebly convex, 

 slightly transverse, at less than twice their length from the base, arcu- 

 ately truncate above; surface rather finely, irregularly, not densely punc- 

 tate, more closely and coarsely at the sides, having a very feeble trans- 

 verse impression at about basal third, wholly interrupted at the middle, 

 the feebly sloping front large and strongly flattened, with a feeble trans- 

 verse impression parallel to the apical margin, which is broadly truncate 

 and with two small distant obtuse lobes; antennae bright rufous, shining, 

 ae long as the entire head, the basal joint large, subglobular, second small 

 and very short, three to six subquadrate, the next two larger and longer, 

 the long loose club with the sensitive inner areas of the first two joints 

 more than a third as wide and more than half as long as the joints; pro- 

 thorax very slightly longer than wide, broadly rounded at base, truncate 

 at apex, with the punctures uniform, deep and moderately close-set, 

 somewhat coarse; scutellum small, elongate, tumid and acutely trian- 

 gular; elytra pedunculate at base, fully as wide as the apex of the pro- 

 thorax, gradually inflated and with arcuate sides posteriorly, rounded at 

 apex, fully twice as long as the prothorax but barely more than twice as 

 long as wide, having regular series of small punctures, becoming obsolete 

 at about apical third, the series impressed thence to the base except in 

 inner half, the intervals with very minute punctures in obscure double 

 series; general surface with numerous coarse creases, especially behind; 

 abdomen very smooth and polished, very minutely and sparsely punctu- 

 late, the last two segments shortest, equal, the fifth broadly and circularly 

 rounded; hind tarsi much longer than the tibiee, the latter somewhat 

 longer than the very short femora. Length 5.0 mm.; width posteriorly 

 1.2 mm. Colorado (Boulder Co.). 



At the base of each elytron there is a steeply sloping, polished 

 transverse omoplate, which is completely divided by a very deep 

 perforate excavation just within each humeral convexity, the hu- 

 meral angles rather obtuse and not denticulated by the omoplate. 

 This is a remarkable structure, which is present also, though much 

 less developed, in cylindricus. The species is evidently allied to 

 caviceps Fall, from the Huachuca Mts. of Arizona, but it is im- 

 possible to state the degree of relationship from the short and rather 

 unsatisfactory description of the latter species, which is unaccom- 

 panied even by a definite statement of the dimensions. However, 

 the head is not concave, though strongly flattened over the frontal 

 regions behind the transverse subapical impression, and the sub- 

 basal transverse impression is so feeble as to be barely traceable, 

 except under very oblique illumination, and is wholly obsolete 

 medially. If caviceps is really like cylindricus in outline, as is im- 

 plied by the author, it is very different from Iceviventris, the posterior 

 inflation of which is a prominent feature and cylindricus, as shown 

 by my single example, is a much smaller species. 



