212 Trans. Acad. Sci. of St. Louis. 



12 — Form rather slender, convex, linear, shining, black, the prothorax and 

 first two ventrals dark piceo-rufous ; legs and autennae piceous, the basal 

 joint of the latter and the tarsi paler; punctures fine, asperate, only 

 moderately close-set, on the anterior parts excessively minute, on the 

 abdomen dense but less so on the first two tergltes; pubescence fine and 

 close but not conspicuous. Female with the head rather small, abruptly 

 narrowed at base, the antennae extending to the middle of the elytra, 

 gradually and strongly incrassate distally, the second and third joints 

 much elongated and equal, the subapical joints not quite as long as 

 wide; prothorax much wider than the head but only just vis'ibly wider 

 than long, the sides broadly rounded at apex, thence feebly converging 

 and nearly straight to the base, convex, the punctular interstices polished, 

 not reticulate, broadly, feebly impressed along the middle except at 

 apex, the latter but little mure than two-thirds as wide as the base; 

 elytra distinctly wider than long, fully two-fifths wider but scarcely 

 more than a third longer than the prothorax, with an oval sutural im- 

 pression behind the scutellum, the humeri rather narrowly exposed, 

 rounded; hind tarsi nearly four -fifths as long as the tibiae, the basal 

 joint about as long as the next two combined; sixth ventral broadly 

 rounded at tip; mesosternal process about attaining the metasternum 

 but rather wider than usual, obtusely rounded at tip. Male not known. 

 Length 2.4-2.7 mm.; width 0.62-0.6 mm. California (Siskiyou, Napa 

 and Sta. Clara Cos.) f aceta Csy. 



Form relatively rather broader and less convex than in faceta, smaller in size, 

 the antennae, tarsi and mesosternal process similar, rather shining, 

 somewhat pale piceo-rufous, the head and posterior part of the abdo- 

 men black; elytra with a fine pale apical margin, the legs and an- 

 tennae toward base pale testaceous, the latter infuscate distally ; pubes- 

 cence and punctuation nearly as in faceta, the asperulate punctures of 

 the pronotum stronger, the very minute punctulation of the abdomen 

 less close-set. Female with the head smaller, orbicular, more gradually 

 and arcuately narrowed toward base ; prothorax shorter and more 

 transverse, nearly a fourth wider than long and very much wider than 

 the head, the sides rather more strongly rounded anteriorly and 

 thence more strongly converging and nearly straight to the base, 

 the surface moderately convex, very obsoletely and much more 

 narrowly impressed along the median line, unimpressed in apical 

 third; elytra nearly similar to those of faceta; sixth ventral rounded 

 at tip. iifaZe not at hand. Length 2.35 mm.; width 0.5 mm. California 

 (Los Angeles Co.), — II. C. Fall Tespertina n. sp. 



In addition to the above species, which are wholly con- 

 generic with such European types as constricta, coarctata and 

 ferealis, of Erichson, and which may be regarded as repre- 

 senting the true Tachyusa^ I have before me certain aber- 

 rant species forming subgeneric groups of the present genus ; 

 these, with the types upon which they are founded, may be 

 briefly indicated as follows: — 



