142 MEMOIRS ON THE COLEOPTERA 



angles obtuse, obtusely subprominent; base equal in width to the 

 apex, four-fifths the maximum width; surface convex, the lateral 

 concave margin moderate, the latero-basal punctures unusually few 

 and fine, the median stria and longitudinal impressions strong; 

 elytra parallel, fully three-fifths longer than wide, a little shorter 

 (9), a fourth to fifth wider than the prothorax (cf), sjightly more 

 (9), the lustre respectively polished or feebly sericeous, the striae 

 fine, irregularly subpunctulate. Length (cf 9 ) n.o-n.S mm.; 

 width 4.0-4.3 mm. Rocky Mountains, from Arizona to Idaho. 

 Abundant in Boulder Co., Colorado. The female much less common 



than the male saxatilis n. sp. 



Body shorter in form, similar in coloration and lustre in both sexes; 

 head nearly similar; palpi testaceous throughout; prothorax much 

 shorter and more transverse, fully a third wider than long, the sides 

 strongly rounded, more strongly converging and nearly straight 

 posteriorly, the angles very obtuse but not rounded and rendered 

 somewhat prominent by the puncture in the bead; base distinctly 

 narrower than the apex and two-thirds to three-fourths the maxi- 

 mum width; surface convex, with rather deep stria and impressions 

 and a larger and denser patch of punctures latero-basally than in 

 the preceding, the sides similarly reflexed; elytra shorter, one- 

 half longer than wide and not wider than the prothorax (cf), or 

 slightly shorter (9). the lustre and striation as in the preceding, 

 except that the striae are less evidently, in fact scarcely at all, punctu- 

 late, the scutellar stria long. Length (cf 9 ) 10.7-11.7 mm.; width 

 3.75-4.2 mm. Colorado Levette collection laxicollis n. sp. 



In the long series of adstrictus before me, there is some diversity; 

 the Fort Wrangel examples, for instance, are a little larger and 

 very slightly more elongate than those from Metlakatla, and the 

 single Siskiyou specimen, which is a male, has somewhat shorter 

 and more posteriorly dilated elytra. It would be exceedingly diffi- 

 cult to work out all the taxonomic forms in this genus, and those 

 named above are the only ones that are obviously distinct by reason 

 of form, sculpture or lustre, combined with habital environment. 

 This diversity in the adstrictus type might have been inferred from 

 the many names already given, there being some published that 

 are not mentioned in the table, such as alternatus and obtusangulum 

 Mots., motschulskyi Makl., and sexpunctatus Mann. The syn- 

 onymy given above under adstrictus is taken from the recent 

 European catalogue of Heyden, Reitter and Weise. The type of 

 vitreus Dej., was from Kamtschatka, and Dejean says nothing about 

 the sides of the prothorax being slightly sinuate behind, with the 

 hind angles right, as stated by LeConte. The separation, also, of 



