BEMBIDIESLE 171 



conspicuous mental foramina and the six entire punctate elytral 

 striae, that may be deemed sufficient to hold them together gener- 

 ically. We have but a single species of this subgenus as follows: 



Body elongate, ventricose, ferruginous, subopaque, the elytra each with 

 a fine darker irregular oblique discal line meeting the suture poster- 

 iorly, and behind which the surface is more flavate: head distinctly 

 narrower than the prothorax, somewhat elongate, the eyes moder- 

 ate, convex; sulci narrow, parallel, remote from the eyes, the orbital 

 puncture minute and distant from the eye; antennae fully as long as 

 the elytra, ferruginous, slender basally, incrassate distally, the fifth 

 joint nearly three times as long as wide, the tenth but slightly elon- 

 gate; prothorax fully as long as wide; base arcuate, four-sevenths 

 the maximum width, much narrower than the broadly sinuate apex; 

 sides broadly reflexed, strongly arcuate anteriorly, oblique from be- 

 fore the middle, sinuate basally, somewhat diverging at the subprom- 

 inent angles; surface convex along the middle, rugulose, the anterior 

 impression shallow, medial and foveiform, the posterior obsolete, 

 represented by a row of punctures; foveae rather large and deep, 

 elongate-oval; stria fine, subentire; carinae wanting; elytra one-half 

 longer than wide, four-fifths wider than the prothorax, oval, gradu- 

 ally acutely ogival behind, the humeri obtusely rounded, the striae 

 coarse, deeply impressed and approximate, the punctures not coarse 

 but strong and close-set in the sulci, the seventh wholly wanting; 

 eighth with the widely separated foveae very coarse, deep and con- 

 spicuous; at the junction of the third and fifth striae there is a sunken 

 tuberculiform setigerous puncture, from which to the apical margin 

 there is a slender carinate channel; dorsal foveae very small, on the 

 third interval at fourth and half. Length (d 71 9 ) 2.7-3.2 mm.; 

 width i .0-1.2 mm. California (Yuma Reservation); also on the 

 Arizona bank of the Colorado River opposite sellatus Lee. 



I found this species in abundance in hoof-prints in the sand of 

 the river bank, under fallen leaves. In the male the anterior tarsi 

 are short, the basal joint short, though not evidently dilated; in 

 the female the tarsus, and especially its basal joint, is distinctly 

 longer than in the male. These tarsal characters are probably 

 analogous to those of Lymneops. 



Group II ephippiatus 

 Subgenus Tachysops nov. 



The habitus of the body in this subgenus is notably different 

 from that of the preceding group, in being more oval, convex, pol- 

 ished, with evenly convex prothorax, the anterior angles of which 

 are not prominent, in the less posteriorly prolonged head and other 



