272 Trans. Acad. Set. of St. Louis. 



Yenasa u. gen. 



In the general form and sculpture, as well as coloration of 

 the body, the species of Venusa closely resemble Stictalia, but 

 they differ in three important features, the first relating to 

 the structure of the antennae, which do not gradually increase 

 in thickness to the tip but are slender at base, with the outer 

 seven joints forming a long and loose, nearly parallel-sided 

 club, the second being the much wider and more transverse 

 prothorax, imparting a notably different facies to the anterior 

 part of the body, the third concerning the sexual characters 

 of the male, the punctures of the fifth and sixth tergites, as 

 in Silusida, not being notably or more coarsely asperate and 

 both having a large conspicuous, though unentire, obtusely 

 rounded ridge along the median line; the sixth is, however, 

 similarly sinuate or sinuato-truncate at tip and armed with 

 porrect denticles throughout the width. The species are not 

 very numerous, closely allied among themselves and swarm in- 

 dividually in great numbers in almost every mushroom that 

 has passed its prime, resembling in this way the allied genus 

 Pleurotohia ; they may be described as follows : — 



Antennae stouter, the penultimate joints much wider than long. Body 

 stout, parallel, convex, shining, black or blackish, the basal margin of 

 the prothorax pale, the elytra pale flavo-testaceous, slightly dark near 

 the scutellum and broadly toward the external angles; abdomen bright 

 red, the fifth tergite and basal half of the sixth black; legs pale, the 

 antennae blackish, pale toward base ; head wider than long, rapidly 

 narrowed behind the eyes, which are well developed and finely faceted, 

 the punctures fine, rather sparse; antennae attaining basal third of the 

 elytra; prothorax three- fourths wider than long, slightly less than one- 

 half wider than the head, rounded at the sides, the latter becoming 

 subparallel toward base, the surface finely, asperately and closely 

 punctate, with a large feeble binary impression at the middle before 

 the base ; elytra wider than long, very slightly wider and one-half longer 

 than the prothorax, impressed at each side of the suture for about half 

 the length behind the scutellum, rather finely, closely but asperately 

 punctate, the humeri scarcely at all exposed at base ; abdomen much 

 narrower than the elytra, somewhat tapering from near the base to the 

 apex, rather finely but strongly, closely and asperately punctate, the 

 impressions rather narrow, moderately deep and somewhat more 

 coarsely and sparsely punctate. Length 2.6 mm.; width 0.82 mm. New 

 York (near the city) to Iowa picta n. sp. (Fvl. MS.). 



