Dec.,x 9 o5] Fall: Affinities of the Genus Tachycellus. 175 



joints; scutellum short and broad, only feebly entering the elytral disk; upper sur- 

 face glabrous, polished; elytra with the sutural stria alone impressed, the others 

 feeble or completely effaced; dorsal punctures wanting; lower surface sparsely 

 punctured and pubescent, tip of presternum plurisetose, abdomen in the male wUh 

 two small densely punctured and pubescent spots (sometimes confluent) on the 

 second and third segments. 



Table of Species. 



Prothorax at sides plurisetose; size large ( S - 7 mm.) color usually «^or m 



great part testaceous ' ' '"" 



Prothorax at sides unisetose, color piceous, usually more or less bronzed, rarely ob- 

 scurely suffused with testaceous. 

 Hind angles of prothorax rectangular or very nearly so, abdominal pubescent 



spots in the $ well separated ; size smaller (3-5-5 mm. ) politus. 



Hind angles of prothorax obtuse, the prothorax more distinctly narrowed poste- 

 riorly • abdominal pubescent spots in the male confluent ; size small. 

 Sides of prothorax slightly sinuate before the hind angles, the latter more 

 sharplv defined ; elytra three times as long as the prothorax. 



r J intermedius. 



Sides of prothorax scarcely visibly sinuate before the angles, which are less 



sharply defined ; elytra two and one half times as long as the prothorax. 



1 - obtusus. 



G. nitidus Dej. . 



This is our largest species and may always be recognized by the 

 numerous marginal setae of the prothorax. These setae are about 

 seven in number and more closely placed in front; there is no seta 

 in the hind angle. The color in California specimens is commonly 

 entirely testaceous, but specimens are frequently seen having two 

 elongate discal spots on the thorax, and a discal stripe on the elytra 

 black The black color is inclined to spread by diffusion, but I have 

 never seen specimens from our territory with either thorax or elytra 

 entirely dark. In a series of Mexican specimens before me the elytra 

 are entirely black in some specimens while in others the entire upper 

 surface is thus suffused. These are the obsoleius of Say. As observed 

 by Bates in the Biologia, the form in the Mexican specimens seems a 

 little more elongate than in those from California, but the difference 

 is elusive and it is probable that Horn was correct in declaring them 

 identical The elytral striae except the sutural, which is always sharply 

 impressed, are very variable. Commonly there are faint traces of one 

 or more discal striae and occasionally these are all discernible ; in 

 many specimens however they are completely effaced. The pubescent 

 spots of the second and third segments are very small and separated 

 by a distance rather greater than their own diameter. 



