164 Trans. Acad. Sci. of St. Louis. 



two groups cannot be considered a generic character in any 

 sense.* The species are readily distinguishable among them- 

 selves, as a rule, by structural peculiarities relating to the 

 intermesocoxal parts, sculpture, antennal characters, length 

 of the basal joint of the hind tarsi and other easily observed 

 features. 



Verna has been inscribed in our lists under the name 

 niiida Grav., but is by no means identical, having longer and 

 more closely punctured elytra and more finely and closely 

 sculptured abdomen ; it is given in the European catalogue as 

 a species different from nitida, but I have seen no European 

 representatives. It varies noticeably, not onh^ in size but to 

 some extent in development of the elytra and density of 

 sculpture, as might be inferred from its very extended range, 

 although bimacidafa, which is even more widelv distributed, 

 is notably less plastic. The southern California innocua 

 closely approaches bimacidata Grav., in general structure, 

 but is rather less stout, having also obviously shorter and paler 

 elytra and a smaller, more parallel prothorax. The male of 

 obsolescens possesses one character which, as far as known to 

 me, is unique in the subtribe, the sixth ventral plate having 

 at tip a small, abruptly incised and acutely angulate cleft, 



* Tins species may be described as follows: — 

 Form moderately stout, parallel, convex, shining, deep black, the e'ytra 

 scarcely visibly picescent, not deflnileiy maculate, tlie legs and antennae 

 black; head fully three-fifths as vFide as the prothorax, finely, remotely 

 punctate, the antennae barely one -half longer than the head, strongly 

 incrassate and compact distally, the second joint much longer than the 

 the third and almost as long as the next two combined; prothorax 

 nearly one-half wider than long, slightly narrower from base to apex, 

 with the sides evenly and strongly arcuate, the base arcuate, the 

 angles obtusely rounded, the punctures very sparse, disposed as in 

 verna throughout; elytra scarcely at all wider than the prothorax and 

 about as long, the suture not quite as long as the median line, the 

 punctures and pubescence as in verna; abdomen parallel, nearly as 

 wide as the elytra, finely, rather sparsely punctured throughout, the 

 punctures of the impressions not larger; mesosternal process narrow, 

 the carina very much abbreviated, not extending quite to the middle 

 of the acetabula; hind tarsi as long as the tibiae, the basal joint fully 

 as long as the fifth and as long as the next two together. Length 

 2.7 mm. ; width 0.83 mm. Mexico (Federal District) . .composita n. sp. 



