33 2 MEMOIRS ON THE COLEOPTERA 



Ischnocnemis Thorns., is not represented in my cabinet; it has 

 for its type a rather large Mexican species, tripunctata Thorns. 

 (costipennis Dej., MS.); it is black, obscure above, the abdomen 

 tawny-testaceous, the elytra densely punctate and having, between 

 the two costse, a broad brown vitta not attaining the apex. The 

 genus Ischnocnemis was evidently misunderstood by LeConte and 

 Horn (Class., p. 301), as the mesosternum is said to be protuberant; 

 this error was noticed also by Bates. 



Entomosterna Chev. 



As limited above to those species agreeing in general with the 

 formula of Lacordaire, but having only one vitta, pale, or apparently 

 sometimes as in cyaneus Bates, not pale, on each elytron, this genus 

 will comprise among others Ischnocnemis ccendescens Bates, as w r ell 

 as the following: 



*Entomosterna unicostata n. sp. Deep black throughout, opaculate, 

 the vestiture above very short and indistinct, silvery white and dense 

 toward the sides of the body beneath; head and pronotum opaque, not 

 very coarsely but extremely densely punctate throughout, the latter 

 with a short smooth and narrow, slightly elevated median line behind the 

 middle; antennae (o 71 ) a little longer than the body, slender, slightly com- 

 pressed and subserrate distally, the third joint two-fifths longer than the 

 fourth; prothorax fully as long as wide, slightly wider behind the middle 

 than at base but with the sides very evenly and moderately arcuate, 

 more converging anteriorly, the apex two-thirds the maximum width; 

 basal angles, formed by the cariniform prolongation of the basal bead, 

 lapping the elytral humeri; scutellum triangular, as wide as long, some- 

 times concave, acute at apex but not prolonged; elytra cuneiform, slightly 

 wider than the prothorax, two and one-half times as long as wide, strongly, 

 very densely punctate, even, excepting the large polished and very strong 

 ivory costa at inner third; apices sinuato-truncate, the external angle 

 acute but not spiniform. Length (cf ) 11.7-12.7 mm. ; width 2.8-3.4 mm. 

 Mexico (Guerrero), Baron. 



To be distinguished very readily from ccerulescens by the dull 

 black surface, very strong elytral costa and other characters. The 

 abdomen and sterna conform to Stenobatyle as described above. 



The genera of the following group differ very much from the 

 preceding though often closely resembling certain of them in the 

 ivory elytral vitta; in the horizontal, sharply limited and anteriorly 

 perpendicular mesosternum and shorter hind tarsi. Plionoma has 

 much the same position in the group that Batyle and other genera 

 with evenly convex elytra have in the preceding group : 



