COLEOPTERA OF BAJA CALIFORNIA. 435 



arcuate anteriorly, hind angles rectangular, disc moder- 

 ately convex, coarsely and closely punctate. Elytra 

 more than twice as long as wide, sides parallel, arcuately 

 narrowing at apical third, the apex slightly sinuate near 

 the suture, the sutural angle prolonged into a spine, disc 

 slightly flattened, finely striate, stria? finely punctured, 

 intervals flat, submuricately punctulate, but not densely. 

 Prothorax beneath densely punctured and opaque, the 

 propleuras near the margin much smoother. Abdomen 

 shining, sparsely finely punctate. First joint of hind 

 tarsus longer than the following joints. Length, .37-.48 

 inch; 9.5-12 mm. 



This species is described with the view of introducino- 

 an element in Hymenorus hitherto unrecorded — the spin- 

 iform prolongation of the sutural angle. I have, in addi- 

 tion, a second species closely resembling occidentalis 

 superficially, with the sutural angle acute, but never with 

 the spine so well developed as in spiuifcr. The species 

 now described is related to occidentalis and is the larcrest 

 species known in the genus. 



Mr. Champion has recorded the spiniform suture in 

 several species of Lobopoda, and, from the yet unstudied 

 material in my cabinet, the fine of demarcation between 

 that genus and Hymenorus is becoming gradually effaced. 



Four specimens. Southern Arizona. 



SiSENES ChAMPIONI U. sp. 



Elongate, nearly parallel male, broader behind female, 

 head and thorax black shining, with a slight tinge of blue, 

 elytra entirely orange-yellow with similar pubescence. 

 Antenna; black, slender in both sexes, third joint shorter 

 than the fourth. Head elongate, sparsely, finely and in- 

 distinctly punctate. Thorax one-fourth longer than wide, 

 widest one-third from apex, sides anteriorly slightly arcu- 

 ate, posteriorly feebly sinuate, disc feebly convex a vague 



