42 MEMOIRS ON THE COLEOPTERA. 



the latter are generally in approximate continuation of the sides 

 of the former; otherwise there is no difference and the group is 

 purely arbitrary. Among the species already described, the group 

 is represented by arnica, found abundantly by Dr. Brendel at Cedar 

 Rapids, Iowa, and ancilla Csy.,a name subsequently changed, first 

 to dubia, by Fenyes, and shortly afterward to caseyi by Bernhauer. 

 The following species i? the largest of this group now known and 

 has the abdominal sculpture even and not very asperate: 



Oxypoda gymnica n. sp. Rather stout, subparallel, convex and sub- 

 alutaceous, piceous-black, the elytra but slightly paler, the legs piceous- 

 brown; punctures fine, somewhat close, rather strong and asperate on 

 the elytra, very fine, close and even though only slightly asperate on the 

 abdomen; pubescence moderately short, palish; head only slightly 

 wider than long, but little more than one-half as wide as the prothorax, 

 parallel and subevenly rounded at the sides, the eyes barely at all promi- 

 nent and at rather more than their own length from the base, the carinae 

 distinct, entire; antennae black, not distinctly paler basally, a little 

 longer than the head and prothorax, the third joint shorter than the 

 second, fourth obtrapezoidal, not quite as long as wide, not much wider 

 than the third, fifth and following rather abruptly wider, forming a 

 noticeably stout and parallel section, in which the joints pass from 

 strongly to feebly obtrapezoidal and from slightly to rather strongly 

 transverse, the tenth a little longer than the ninth, the last distinctly 

 shorter than the two preceding; prothorax fully one-half wider than long, 

 the sides strongly converging and broadly rounded from base to apex, 

 becoming subparallel basally, convex, with a feeble ante-scutellar im- 

 pression; elytra large, slightly shorter than wide, subparallel, at base 

 fully as wide as the prothorax, the suture a third longer, the apices 

 moderately sinuate laterally; abdomen nearly parallel, with straight 

 sides, distinctly narrower than the elytra, narrowing slightly posteriorly 

 but only through the fifth tergite, which is a fourth longer than the 

 fourth. Length 2.68-2.8 mm.; width 0.65-0.73 mm. Arizona (Williams), 

 VVickham. 



Very distinct from any of the following species in its stouter form 

 and parallel abdomen. 



In the following five species the abdominal sculpture is as in 

 the wickhami-nigriceps group preceding; that is, comparatively 

 coarsely asperate, the punctures coarser, more longitudinal and 

 sparser apically : 



Oxypoda sedula n. sp. -Rather slender, dark piceous-brown, the 

 pronotum and abdominal apex paler and more ochreous; punctures 

 minute, close, slightly asperulate on the elytra, coarser and less close 

 on the abdomen, especially toward tip; lustre anteriorly alutaceous, the 



