402 THE CANADIAN ENTOMOLOGIST. 



one of the most depressed and compact species known at present and 

 evidently valid. 



The genus as restricted in my Revision may be divided into two 

 primary sections, the first having the black thoracic area extending broadly 

 to the anterior edge, the second having the black area separated therefrom 

 by a more or less broad complete pale border. The first section com- 

 prises most of the large species with tendency to transverse fasciation of 

 the elytral markings. The second is divisible into three minor grou!)s, 

 represented by g-notaia^ perplexa and tricuspis. In the first section there 

 are several primary type forms, represented by ^-notata, monticola and 

 Califoniica respectively. To \\\^ ^-notata group belong in addition only 

 nugatoria^ Johnsoni and Sonorica. The monticola group includes as 

 species monticola^ with impressa^ differing in sculpture but probably a 

 subspecies, the distinctly isolated suturaiis, ahiiacea, much larger, more 

 convex and with a much more pronounced posterior prolongation of the 

 lateral thoracic white area, pj-olojigata, with very irregular white lateral 

 area, which, by a transverse spur, tends to form a partial apical white 

 margin bordering the black area, and difficilis. 



The Californica group includes besides only Nevadica, agreeing in the 

 total absence of discal spots on the elytra but differing in its more broadly 

 oval form, pale and not blackish sutural edges, and, more particularly, in 

 its much coarser, denser and more conspicuous punctuation. 



The first group of the second section includes g-fiotata, degener and 

 Oregona,, the last two of which may be regarded as subspecies. The second 

 group is composed o( pefplexa, subversa, with subspeciesy>///<^z;^^, of which 

 barda is a synonym, and Eugenii^ the latter a valid species. The third 

 group consists of the remarkably isolated tricuspis alone. 



The following are the new species or subspecies mentioned above : 



C. Sonorica, n. sp. — Large, broadly oval, very convex, rather shining, 

 finely and inconspicuously punctate; head with the usual juxta-ocular 

 spots ; pronotum with a moderate quadrate spot at each angle, extending 

 posteriorly only to the middle, the black, however, ascending along the 

 edge almost to the angle, the entire hypomera black except at tip ; elytra 

 with a large transversely biangular scutellar spot, a thick transverse spot 

 on each at the middle, from inner fourth to outer third, without trace of 

 additional external spot, and a subapical similar spot from inner third 

 to outer sixth. Length, 6.2-7.0 mm.; width, 4.8-5.4 mm. Mexico 

 (Colonia Garcia, Chihuahua), Townsend. 



