176 THE CANADIAN ENTOMOLOGIST. 



Brachycrepis n. g. 



This genus is very similar to Rhopalicus Forster, but the prolonged 

 metathorax has three distinct keels, the abdomen has a short rugose 

 petiole, the marginal vein of the front wings is but slightly longer than 

 the stigmal and the parapsides complete. The anterior femora are very 

 much swollen ; the antennae are subclavate, 13-jointed with two ring joints, 

 and are inserted slightly below the middle of the face ; the pedicel is about 

 as long as the first funiclar joint. 



Bi'achycrepis tricarinatus n. sp. 



°. Length .13 inch. Dark blue with a slight metallic tinge on the 

 head and thorax, confluently punctured. Eyes dark brown. Antennae 

 13-jointed, black, except the scape beneath, which is brownish-yellow ; 

 flagellum pubescent ; the first funiclar joint the longest, the others slightly 

 subequal, but gradually growing wider toward the club, the fifth and sixth 

 joints being wider than long. Collar transverse, narrowed in the middle. 

 Mesothoracic grooves distinct, but very delicate as they approach the 

 scutellum. Coxae, femora and tibiae, excepting their tips and the last 

 tarsal joint, blue-black ; tips and the other tarsal joints, honey-yellow. 

 Abdomen long ovate, about the length of the thorax, blue-black with a 

 very slight metallic tinge near the base beneath. The second segment, 

 counting the petiole as the first, is the largest, the others gradually sub- 

 equal ; each segment with a single row of delicate white hairs. Wings 

 hyaline ; veins pale brownish, the submarginal vein as long as the marginal 

 and postmarginal together, delicate, the marginal is but slightly longer 

 than the stigmal, the latter clavate with a slight uncus. 



Hab. — Riley Co., Kansas. Prof. E. A. Popenoe. 



CAN INSECTS DISTINGUISH BETWEEN RED AND YELLOW ? 



BY T. D. A. COCKERELL, WEST CLIFF, COLORADO. 



In this neighborhood (Custer Co., Colorado,) one very frequently finds 

 a yellow spider of the genus Tiiomisus or allied thereto, seated in the 

 middle of the umbels of Ligusticum montanum Benth. and Hook., and 

 on other yellow flowers. This spider, so seated, has nothing to cover it 

 from direct observation, and from its size and colour would be conspicuous 

 enough elsewhere ; but on the yellow flower, sitting in the depression in 



