204 Trans. Acad. Sci. of St. Louis. 



extremely miDutely and densely asperulato-punctate, the abdomen 

 particularly densely so, dull in lustre, the head rather less densely 

 sculptured and more shining; head fully as long as wide, the eyes large 

 and rather convex, the terapora short behind them; surface very feebly 

 impressed along the median line of the vertex; antennae very long and 

 slender, extending rather beyond the tips of the elytra, very feebly in- 

 crassate distally, the joints elongate, the three penultimate as long as 

 wide, the eleventh slender, as long as the two preceding combined; 

 prothorax scarcely visibly wider than the head and very slightly wider 

 than long, widest at apical third, where the sides are broadly rounded, 

 thence-feebly convergentand straight to the base, which is feebly arcuate ; 

 surface obsoletely impressed along the median line almost through- 

 out, not at ail transversely impressed before the scutellum; elytra 

 two-fifths wider and a third longer than the prothorax, the humeri 

 somewhat exposed at base, rounded ; abdomen not quite as wide as the 

 elytra, parallel, with evenly and conspicuously arcuate sides, the tergites 

 flat; legs long and slender. Length 2.0 mm. ; width 0.6 mm. Texas 

 (Brownsville),— H. F. Wickham alatacea n. sp. 



The sixth ventral of the male appears to be very broadly 

 and feebly bilobed at tip. 



Tachyusa Erichs. 



The approximation to this genus in general appearance 

 made by certain forms of Gnypeta, especially the slender and 

 sublinear species of the abducens type, has been alluded to 

 above. The species here assigned to Tachyusa are perfectly 

 homogeneous, however, and may be distinguished from any 

 Gnypeta, even those in which the abdomen is posteriorly di- 

 lated, by the more approximate middle coxae and the more 

 slender and generally very acutely pointed, though equally 

 free, mesosternal process attaining the metasternal projection 

 or virtually so, the intervening depressed isthmus of Gnypeta 

 being obsolete or extremely short. They are also distinct 

 from that genus in their more attenuate form and especially 

 by the relatively more slender claviform abdomen, in which the 

 deep basal impressions of the first three tergites are arcuate 

 and not straight and are carinate in the middle, the carina 

 joining the elevated basal margin through a posteriorly pro- 

 jecting cusp which I have never noticed in Gnypeta; the de- 

 pressions are always very coarsely punctate and so densely so 

 that the intervals are acutely elevated, forming short longi- 



