240 . [LeConte. 



3. Club of antennae annulated 4. 



" of antennae solid EURHOPTTJS. 



4. Claws very small, approximate ACALLES. 



" larger, divergent. MICROMASTTJS, 



5. ' ' slender, divergent P SEUDOMUS. 



6. Tibiae strongly compressed 9. 



" slender, more or less sinuate 7. 



7. Mesosternum deeply emarginate 8. 



feebly " TYLODERMA. 



8. Claws appendiculate, divergent PHYRDENUS. 



' ' simple, divergent : OR YPT ORH YNCHTJS. 



9. Tibiae not serrate 1O. 



" more or less serrate ZASCELIS. 



10. First ventral suture deep CCELOSTERNUS. 



" sinuate, faint at the 



middle BAROPSIS. 



ACALLES Sen. 



The very short metasternum, with indistinct episterna, the oval elytra 

 with rounded sides, and the small tarsal claws will enable the species of 

 this genus to be easily recognized. The mesosternum is usually deeply 

 excavated for about one-half its length, so that the pectoral groove ends 

 about the anterior limit of the middle coxae; but this is not the case with A. 

 nuchalis and pectoralis; the hind part of the mesosternum is protuberant, 

 so as to make an obtuse angle with the metasternum. The distance from 

 the middle to the hind coxae is not greater than from the middle to the front 

 pair; the mesosternum at the side appears longer than the metasternum, a 

 very unusual character in Coleoptera. The last two species described below 

 are anomalous, and when studied in connection with the foreign species, 

 will probably be considered as constituting new genera; in A. nuchalis 

 the metathoracic side pieces are as distinct as in Cryptortiynchus; in A. 

 pectoralis, the mesosternum is scarcely more emarginate than in Tyloderma. 



Mesosternum deeply emarginate 2. 



broadly " 12. 



2. Scales thick, erect, without intermixed bristles 3. 



" appressed, with bristles intermixed 7. 



3. Elytra with conspicuous pale markings 4. 



" not conspicuously marked 5. 



4. Black, with large, posthumeral spot, and band be- 



hind the middle of elytra white 1. nobilis. 



Black, with sub-basal band and a few spots white. . 2. basalis. 



5. Elytra not tesselated 6. 



" with brown scales, tesselated with paler 3. porosus. 



6. Interspaces of elytra moderately wide 4. turbidus. 



" " very narrow 5. clathratus. 





