1 6 MEMOIRS ON THE COLEOPTERA 



Form rather more elongate, black, shining, with only the faintest bronzy 

 lustre, the under surface piceous, the legs paler, rufous; pubescence 

 scantier than in either of the preceding, the elytra only very faintly 

 variegated with irregular patches of very short silvery hairs; head 

 and prothorax nearly as in the preceding, except that the small 

 punctures of the pronotum are still more minute and less close-set 

 medially, becoming still sparser and almost invisible laterally; 

 scutellum much less pubescent; elytra rather more elongate and 

 still more rapidly and obtusely ogival at apex, somewhat less arcuate 

 at the sides and a little more rapidly rounding posteriorly, the stria- 

 tion as in tessellata, the punctures everywhere sparse and extremely 

 minute; abdomen closely but finely and unusually feebly punctato- 

 rugulose. Length 2.8-3.0 mm.; width 1.5 mm. Colorado. 



subnuda n. sp. 



It is assumed that the species named tessellata in the table, not 

 rare in the elevated parts of New Hampshire, is the same as that 

 referred to in two brief lines by LeConte as inhabiting the southern 

 shore of Lake Superior; I found one example at the extreme summit 

 of Mt. Washington and it is probably widely diffused in the colder 

 regions of the continent. It is however not the same as the Euro- 

 pean metattica, being more elongate in form and much less broadly 

 obtuse posteriorly. All of the above species are more elongate 

 than any of the four European species in my collection; excepting 

 acuminata Er., and that is much smaller and of radically different 

 sculpture and vestiture. 



Tribe BYRRHINI. 



The chief outward character of this tribe is the stout oval and 

 convex body, with finely, very densely punctured, densely pubescent 

 integuments and deeply retractile legs. The elytral striae are more 

 or less fine, having the nature of abruptly formed shallow grooves 

 not impressed lines as in the preceding tribe and are almost 

 regular, the three or four beyond the sutural not entire but never 

 joining the sutural stria; occasionally the striae are represented 

 merely by series of detached punctures. The antennae are short, 

 very gradually stouter distally and with the third joint elongate, 

 not differing materially from the usual form in the preceding tribes, 

 and the abdominal sutures are all distinctly arcuate. The six genera 

 known to me may be defined as follows : 



Fossae for the hind legs deep though rather gradually formed, without 

 prominent margins; upper surface never having erect setae; size 

 moderate to rather large 2 



