BY THOMAS G. SLOANE. 437 



Genus Rhytisternus. 



2'ahJe of Species of Rhytist'-.rnus knoivn to me. 

 T. Unicolorous species (black or piceous-black). 

 A. Elytra with strongly impressed striae. 



a. Sides of prothorax roundly narrowed behind without any 



trace of sinuosity before base, Ijasal angles not marked. 



b. Form narrow, convex R. solidus, SI. 



bh. Form depressed 



E. cyathoderus, Chaud., A: R. splendidits, Blklx* 



aa. Sides of prothorax lightly but not roundly narrowed to 

 base, basal angles obtuse. 



c. Form stout, convex R. bovilli, Blkb. 



cc. Form depressed R. Icevilaterus, Chaud. f 



aaa. Sides of prothorax sinuate or sul)sinuate before base, 

 basal angles marked. 



d. Interstices of elytra not convex posteriorly 



R. nigellus, SI. 



dd. Interstices of elytra convex. 



e. ^Prosternal episterna not perceptibly strigose, humeral 



angles shortly but distinctly dentate R. gigas, SI. 



ee. Prosternal epistei-na longitudinally strigose, humeral angles 

 without any dentiform projection. 



f. Prothorax but little broader than long, size small 



A', miser, Chaud. 



ff. Prothorax transverse, size large. 



g. Five decidedly convex interstices on each elytron 



R. carpenlariiis, SI. 



"The differences between /'. rv«//torZ(-rHx, Chaud., and R. f>plendidus, 

 Blkb., are more of a general than a particular character, and are not 

 easily tabulated. The smaller .size and the longer prothora.x more narrowed 

 to the base of B. splendidus are perhaps the most easily noted characters 

 distinguishing it from i?. cyathoderiix. 



f = B. sidcatipes, Blkb. 



