i8 MEMOIRS ON THE COLEOPTERA 



Cytilus Erichs. 



There are probably a number of true species in this genus, but 

 they are so very closely allied among themselves that it is hardly 

 worth while to define some of them as having more than subspecific 

 value. Our forms, as a group, are more elongate or more oblong 

 than the European and the almost hemispherical sericeus Forst., 

 does not occur here so far as detectible among my rather extended 

 material. Our species may be briefly described as follows: 



Oblong-oval, very convex, black, with feeble blackish-bronze lustre 

 which is more pronounced on the alternately more shining strial 

 intervals, the bronze becoming frequently bright green; under sur- 

 face black, the legs throughout piceous-black; pubescence above 

 short, close and irregular, very short, cinereous and somewhat even 

 on the pronotum but fulvous and streaming radially in a median 

 basal area; scutellum densely aurato-pubescent, the hairs directed 

 transversely from the median line; elytra with the intervals not 

 more than very faintly alternating in convexity, all virtually flat, 

 alternately dull, densely, finely and evenly sculptured with even 

 prostrate blackish and partly cinereous hairs, and a little broader, 

 more lustrous, less densely sculptured and with the pubescence 

 black and in separated irregular areas, producing a tessellated effect; 

 under surface finely, very closely punctured throughout and with 

 very minute inconspicuous pubescence; head strongly, densely 

 punctate and with very short inconspicuous pubescence; prothorax 

 twice as wide as long, very strongly narrowed from base to apex, with 

 scarcely at al! arcuate sides, very declivous and distinctly compressed 

 laterally toward apex, the anterior angles advanced and very acute, 

 the punctures fine, close and even throughout, parted by a fine smooth 

 median line; elytra about a fifth longer than wide, very obtusely 

 rounded at apex. Length 5.2-54 mm.; width 3.25-3.4 mm. New 

 Hampshire, Pennsylvania, Canada and Lake Superior. [Byrrhus 

 alte.rnatus Say, J. Ac. Phil. 5, 1825, p. 186: B. trivittatus Melsh., 



Pr. Ac. Phil., II, 1844, p. 117] alternatus Say 



A Similar throughout to alternatus, except that the body is slightly 

 smaller and still less broadly oval, with the strial intervals more 

 evidently convex, especially on the flanks, where the punctures of 

 the striae are very much more evident. Length 4.5-5.0 mm.; 

 width 2.8-3.1 mm. California (Truckee and Lake Tahoe). 



mimicus n. subsp. 



B Similar to alternatus but larger and still more elongate, the elytral 

 flanks perfectly similar and not modified as in mimicus; entire elytra 

 frequently vivid green. Length 5.2-6.0 mm.; width 3.0-3.3 mm. 

 Washington State and British Columbia to Colorado; those from 

 the last-named region more sober in coloration. 



longulus n. subsp. 



Oblong-oval, shorter than alternatus, rather dull in lustre, black, without 

 metallic glint; somites similarly formed, the vestiture of the upper 



