58 MEMOIRS ox THE COLEOPTERA 



but not deep, the lateral pit isolated; pubescence wanting in the type; 

 scutellum finely, sparsely punctate; elytra fully two-fifths longer 

 than wide, two-fifths wider than the prothorax, feebly cuneiform, 

 with broadly arcuate sides, the edge sinuate slightly behind the base; 

 costse 2-3-5-6-8 and 9 much finer than the sulci and smaller and 

 less elevated than 4 and 7, the punctures coarse but shallow and 

 not well defined; pygidium with rather close and fine, transversely 

 interlacing lines, moderately tumid subapically; tooth of the anterior 

 tibiae near the base of the process, very short and broad and so 

 obtuse as to be virtually rounded; hind legs long. Length (cf) 10.0 

 mm.; width 4.7 mm. Mexico (Colonia Garcia, Sierra Madre Mts., 

 Chihuahua), Townsend *sonorica n. sp. 



The variations in form and continuity of the basal thoracic bead, 

 alluded to above under several species, is a very useful and distinct 

 indication of specific difference that does not seem to have been 

 noticed by Mr. Bates in dealing with the numerous Mexican species, 

 many of which he unites under the name sulcipennis Burm. This 

 species, as described by Burmeister, I do not seem to have at present, 

 but pimalis approaches it rather closely in its metallic coloring, 

 though specifically different; it is in no way closely allied to arbori- 

 cola as stated in the check-list of Mr. Henshaw. I have not seen 

 viridicollis Schf., and draw the above characters from his original 

 description. A specimen before me from New Mexico seems so 

 close to it, however, that it is better not to define it at present; 

 it is 8 mm. in length, much more slender, and more narrowly oval 

 than arboricola and has costse 4 and 7 more elevated than the others 

 as in sonorica; it agrees completely with the coloration of viridicollis 

 as described by Schaeffer, but the prothorax seems to be much less 

 transverse, being only a third wider than long and the lateral 

 fossae are almost obsolete. Irregularis is a singular form and for 

 some time I was under the impression that it might be nothing 

 more than a deformed specimen of arboricola, but the elytral 

 sculpture between the first and fourth costae and elsewhere, as 

 described, is so peculiar that I have ventured to define it and assign 

 it a place subordinate to arboricola provisionally; the very small 

 antennal club was an important factor in reaching this decision. 

 The somewhat prominent convex eyes of angustula constitute a 

 remarkable feature of that distinct species, the exact habitat of 

 which is unknown at present; it is unlike arboricola in habitus, 

 though nearly similar in coloration. 



