NATURAL SCIENCES OF PHILADELPHIA. 353 



Mas segmento ventrali sexto prominulo, profunde foveato. 



Two males, Fort Crook, California, Dr. G. H. Horn. It resembles in form 

 P. convergens, but that species is much larger and uniformly pubes- 

 cent, whereas in the present species the coarse pubescence on the elytra is 

 intermixed with somewhat longer suberect hairs of the same color ; the long 

 erect hairs observed on the head and thorax of the species of the next divi- 

 sion are wanting, and I have therefore regarded it as properly placed next to 

 P. convergens. 



9. P. an t en n at us. Trichochrous ant. Motsch. Bull. Mosc. 1859, ii. 394. 

 Dasytes griseus Lee, Proc. Ac. Nat. Sc. Phil., vi. 169. 



One specimen found by me at San Diego, Cal. ; others from the plains near 

 the Rocky Mountains were given me by Mr. Ulke. This species is easily re- 

 cognized by the thorax being broader than long, gradually but strongly 

 narrowed in front, with the sides feebly rounded, and the hind angles obtusely 

 rounded ; the elytra are coarsely punctured, and clothed with long brownish 

 pubescence; the antennae are piceous, somewhat paler at base ; the fifth joint 

 is obviously wider than the sixth in the female, and the feet are ferruginous ; 

 The last ventral segment of the male is longitudinally broadly impressed, a 

 character I have not observed in any other species of the present group. 



10. P. brevicornis. Dasytes br. Lee, Proc. Acad. Nat. Sc. Phil., vi. 169. 

 San Diego and Middle California. The pubescence is coarse, and the sides 



fringed with very long hairs ; the thorax is broader than long, equally nar- 

 rowed at base and apex, with the sides much rounded ; the elytra are coarsely 

 and more densely punctured than in the preceding ; the antennas are piceous, 

 sometimes nearly testaceous at base ; the third joint is scarcely narrower 

 than the fourth. 



11. P. erythropus. Dasytes erythropus Lee, Pr. Acad. Nat. Sc, vi. 170. 

 Texas. The pubescence is coarse and dense, and the sides of the thorax 



somewhat serrate ; the spines of the anterior tibiae are small, and not very 

 distinct, so that this species might readily be referred to Listrus. Its 

 natural affinity seems to be, however, with the preceding, from which it dif- 

 fers by the narrower form, by the thorax being more strongly rounded on the 

 sides, with the base not at all wider than the apex, and by the much less 

 coarse punctuation of the elytra. 



Group III. Emmenotarsus Motsch. 



The species of this group resemble in form those of the preceding, but 

 differ in having long, erect, black hairs intermingled with the finer prostrate 

 pubescence ; in b r e v i p i 1 o s u s, however, the erect hairs are gray, and but 

 little longer than the pubescence, so that without careful examination they 

 might be overlooked. The row of spines on the outer margin of the anterior 

 tibias is more conspicuous than in most of the species of the preceding group. 

 The sixth ventral segment of the males is visible and concave beneath. 



12. P. brevipilosus, elongatus convexus, fusco-niger, asnescens, pube 

 sordidabreviuscula dense vestitus, capite thoraceque parce punctulatis pilis 

 longis erectis intermixtis, hoc latitudiue breviore antrorsum haud angustato 

 base valde, lateribus late rotundatis, angulis posticis obtusis parum distinctis ; 

 elytris thorace haud latioribus sat dense punctatis, pilis erectis brevibus inter- 

 mixtis vix conspicuis, margine laterali pilis longioribus fimbriato. Long. 4 mm. 



Middle California. A species of more cylindrical form than usual, and 

 easily known by the mtermixed hairs of the elytra being of the same color as 

 the pubescence, and scarcely longer than it. 



13. P. hirtellus, modice elongatus, fusco-asneus, pube sordida longa 

 densissime vestitus, pilisque elongatis erectis intermixtis. Capite thoraceque 

 punctulatis, hoc latitudine breviore, antrorsum sensim angustato, basi valde, 



1866.] 23 



