Sept.-Dec, i9i8.] Van Dyke: Review OF Genus Silis. 173 



ture, by its having the red area of the pronotum completely bisected. 

 In the female, the spot is almost bisected. The more rugose elytra 

 of vulnerata will generally enable that to be separated as will also 

 the rugose elytra of riigosa that species. Lutea is found more or 

 less widely distributed throughout western Oregon and the more 

 western parts of northern and central California, while filigera is 

 confined to a narrow coastal strip of land. Specimens have been 

 taken at Santa Barbara, Cal., the type locality, Carmel Bay, Cal., 

 Fieldbrook, Humboldt Co., Cal, and Tenino, Wash. Of the three 

 coastal black forms, this therefore has the greatest distribution for 

 rugosa only ranges from Marin to Mendocino Co., Cal., and maritima 

 along the coast of Oregon. (Plate IX, fig. 8.) 



Silis spatulata Lee. 



Silis spatulata Lcc, Trans. Amer. Eiit. Soc, Vol. IX (1881), p. 57. 



This eastern black species resembles percomis, as I have stated 

 before, but it appears to be much scarcer. It has been recorded from 

 Illinois, the type locality, and Indiana (Blatchley), and I have seen 

 specimens from Ithaca, N. Y., Plummers Is., Md., and Tryon, N. C. 

 (Plate IX, fig. 9.) 



Silis deserticola new species. 



Elongate, large, rather dull, slaty black with entire thorax orange. Head 

 as broad as apex of prothorax, depressed between the eyes ; eyes prominent, 

 antennae filiform and reaching three fourths length of body. Prothorax almost 

 a semicircle in outline, one fourth broader at bast than long, apex broadly 

 rounded, sides in front almost straight and widely divergent backwards, the 

 posterior incisure deep and broadly opening almost directly outwards, the an- 

 terior angle of the same acute, prominent, divergent, and with its posterior 

 margin reflexed and cariniform, the posterior angles small and acute, the 

 posterior process a blunt spine of moderate length projecting directly out- 

 wards from beneath the posterior angles, the base broadly lobed and including 

 processes, of same breadth as base of elytra, the disc with deep foveae just 

 within the incisures and with distinct longitudinal sulcus at middle. Elytra 

 about six times as long as prothorax, slightly wider posteriorly, moderately 

 coarsely, closely punctured, somewhat scabrous, and with an evident though 

 short white pubescence. Beneath shining in front and dull and rugose over 

 abdomen. Length 7 mm., breadth 3 mm. 



Type and paratype in the collection of the United State Museum, 

 collected in the Argus Mountains, a desert range of southeastern 

 California, May, 1891, by Albert Koebele and marked Type and Para- 

 type, Cat. no. 21694, Argus Mts., Cal. (Koebele). 



