THE PSEUDO CLi'CIv BEETLES. 



775 



ually narrowing to front, surface sparsely and rather coarsely punctured ; 

 carina} of hind angles extending two-thirds to apex. Elytra slightly wider 

 than thorax, not striate, sparsely, finely and irregularly punctate. Length 

 4 mm. 



Southern half of State; frequent. May 25-June 26. Occurs 

 especially on flowers of milkweed. 



D. quadripustulaius Bonv., more robust, thoracic carinas shorter, 

 length 4 mm., ranges from Wisconsin to Florida and has been re- 

 corded from Cincinnati. D. nitidus Melsh., wholly piceous black, 

 length 4 mm., is known from Pennsylvania. 



II. TiiROSCUS Lat. 1796. (Gr., "to leap upon. ") 



In this genus the antennas vary in the two sexes. In the male 

 the club is one and a half times the length and three times as broad 

 as all the preceding joints together ; in the female it is very little 

 longer than the six preceding joints and not more than twice as wide 

 as they. The eyes of the male are larger and less separated in 

 front. Four species have been taken in the State. 



KEY TO INDIANA SPECIES OF THROSCUS. 



a. Eyes entire. 



J). Strife of presternum much shortened. 



c. Hind angles of thorax without trace of carina. 1476. punctatus. 

 cg. Hind angles with a distinct but short carina close to the side mar- 

 gin, 1477. invisus. 

 hb. Strise of prosternum entire or nearly so ; hind angles not carinate. 



1478. constrictor. 



aa. Eyes with a narrow oblique impression very nearly dividing them into 

 two equal portions; stria? of prosternum entire; elytral intervals with 

 two rows of punctures. 1479. chevrolati. 



1476 (4547). Throsctjs punctatus Bonv., Monog. Throscidse, 1859, 15. 

 Oblong, convex. Dark brown, moderately shining, sparsely and very 



finely pubescent. Thorax nearly twice as wide as long, sides strongly con- 

 verging from base to apex, disk distinctly depressed on basal third, coarsely, 

 equally and rather closely punctate. Elytra not wider than thorax, striate, 

 stride rather closely punctate; intervals flat, each with two rows of close- 

 set punctures which are almost as large as those of stria?. Length 3-3.5 mm. 



Vigo County; rare. May 28, In a specimen at hand the elytra 

 are reddish-brown and the thorax piceous. 



1477 (4548). Throscus invisus Horn, Trans. Amer. Entom. Soc, XII, 



1885, 201. 



Resembles punctatus but somewhat larger, darker and more robust, 

 with the basal region of thorax less impressed, the punctures of disk more 

 widely separated and a fine but distinct carina close to the margin on hind 

 angles. Length 3.5-4 mm. 



