CERAMBYCIDAE. 315 



Entomosterna, instead of forming of it the new genus indicated 

 but not named by Lacordaire.* 



Of the genera tabulated above Stenaspis and Tragidion occur 

 from the Atlantic to the Pacific in the warmer regions, the former 

 extending northward in the central region, the latter in the 

 Atlantic district. Purpuricenus occurs in the Middle and 

 Western States. The next three genera are found in Texas, and 

 Batyle occurs in the Atlantic region especially southward. 



The genus last named is placed by Lacordaire in Hcteropsides, 

 of which he observes that the middle coxal cavities are closed 

 externally ; I find, however, in my specimens that the mesotho- 

 racic epimera attain the coxal cavities, and that they are as open 

 as in Purpuricenus. The character as used by Lacordaire seems 

 to me very deceptive, and without value for systematic results. 



Group IV. — Tyloses. 



Closely related to the preceding, and only differing in fact by 

 the mandibles not being acute at tip, but truncate, forming a 

 chisel-shaped edge, which is emarginate. The front is moderate 

 in size, nearly perpendicular, and the antennal tubercles are not 

 much elevated; the genae are not elongated. The scutellum is 

 small, acutely triangular, and the stridulating plate of the meso- 

 notum is large. The side pieces of the metasternum are toler- 

 ably wide, not narrowed behind, and the scent pores are distinct, 

 except in Perarthrus vittatus and Sphaenothecus bivittatus. The 

 legs are slender, thighs not clavate, tibial spurs rather long, hind 

 tarsi with the 1st joint equal to the two following ; less .slender 

 in Tylosis and Crossidius than in the other genera. The antennae 

 are slender, with elongate sensitive spaces near the carina of the 

 under margin. The last joint of the palpi is subcylindrical, and 

 impressed, as usual, in the other groups of this tribe. 



Our genera, which are found mostly in Texas, Arizona, and 

 Lower California (Crossidius alone extending into Colorado, 

 California, and Oregon), may be tabulated thus : — 



A. Elytra without ivory vittae ; 

 Prothorax with an acnte lateral spine; 



Eyes not divided (pubescence fine). Oxoplus. 



Eyes divided (pubescence coarse). Schizax. 



* Gen. Col. ix, 184, note 3. 



