32 GEO. H. HORN. 



Last abdominal segment nearly nude, frequently ferruginous in color: 



Body finely and evenly, sericeous pubescent lithophilus. 



Body coarsely pubescent.* 



Basal thoracic region and sutural space glabrous fastigiatus. 



Surface everywhere pubescent. 



Alternate interspaces more convex striatus. 



Interspaces flat '. suturalis. 



H.productus, Lee. Proc. Acad. 1852, p. 43. 



Our largest species, easily kaown by the last segment of the abdo- 

 men being as densely coated with scaly hairs as the other segments. 

 The thorax is nearly square in the males and broader than long in the 

 females.; surface rather coarsely punctured and sparsely pubescent. 

 Elytra elongate, subparallel on the sides, striae firmly impressed, with 

 not large punctures, surface more densely pubescent on the sides. 

 The sutural space, which becomes wider behind, is less densely pube- 

 scent, and the hairs are finer, more silken and more easily removed. 

 In this and the other California species the surface becomes coated 

 with a whitish material, so thick and dense as almost completely to 

 hide the pubescence. This is especially the case in those specimens 

 found in streams the waters of which are strongly impregnated with 

 earthy salts, and in specimens taken near the end of the season the 

 legs have been found so completely covered with this incrustation as 

 almost to interfere with their motion. Length .24 — .32 inch j 6 — 8 

 mm. 



This species is widely distributed occurring from near Santa Bar- 

 bara, in the Coast Range, to Tejon, thence in the streams to Yuma, and, 

 in places, along the Gila and San Pedro Rivers, of Arizona, as far as 

 Camp Grant. The original specimens were found at San Diego and 

 Mr. Gabb brought others from the Peninsula. 



H. lithophilus, Germ. {Elmis), Ins. Spec. Nov. 88; Lee. Proc. Acad., loc. cit. 



This species is too well known to need comment. It may be readily 

 known by the dense and evenly distributed sericeous coating with a 

 slightly bronzed lustre. The legs are more glabrous than on other 

 species and, as in all those which folljw, the last ablominal segment 

 is almost entirely deprived of its pubescence and is reddish in color. 

 The profile of the elytra from the scutellum to apex is a regular curve. 

 Length .20 inch ; 5 mm. 



* The pubescence is variable in its quality and distribution. That along the 

 suture, being finer, is frequently rubbed off, either by the motions of the insect 

 when alive or by frictioa against others in transportation. In one spe- 

 cies there is a basal thoracic and a sutural space of the elytra normally devoid 

 of pubescence. 



