1358 FAMILY LXIV. MBLOIDiE. 



c. Front femura with a silken, liairy si)Ot on the under side; se<;ond 

 joint of autwmie very short; mandibles short. VI. Epicauta. 

 ri\ Front femora without a silken, li.-iiry spot. 



,7. Antennae filiform, the outer joints eylindrioal. VII. I'ykota. 



lid. Antemiie thicker toward aiiex, the outer joints oval or rounded. 



e. Labrum deeply emarginate. VIII. Pomphoposa. 



re. Labrum slightly emargin.-ite. Caxthaeis. 



V. :\Iacrobasis Lec. 1862. (Gr., "long + a base.") 

 Our species of this genus are elongate, suhcylindrical, black 

 beetles clothed with gray pubescence and having the first joint of 

 antenna? of male elongate and the second joint always more than 

 half the length of third; last joint of maxillary palpi triangular and 

 obliquely trancate ; front thighs with spot of pubescence as in Epi- 

 cavfa. to which the genus is very closely related. 



KEY TO INDIANA SPECIES OF MACKOBASIS. 



a. First joint of antenna^ unlike in the sexes, that of the male being much 

 thickened and longer than the next two; second joint of male equal 

 lo third and fourth together; length not over l.'i mm. 

 h. First joint of male antenme more or less .S-shaped or with a distinct 

 sinuation on under side near apex ; front tibife of male with one 

 terminal spur. 2519. torsa. 



J)J). First joint of male antemioe not sinuate or S-shaped. but slightly flat- 

 tened and feebly curved ; front tibiaa of male with two spurs. 

 c. Pubescence less dense, ash-gray ; basal joint of male antenuie longer 

 and wider, reaching the occiput; femora without long hairs be- 

 hind in either sex. 2,520. txicoloe. 

 cc. Pubescence more dense and with a distinct yellowish tinge ; basal 

 joint of male antennae not rcacliing the occiput; femora of male, 

 especially the hind (jues, clothed with long hairs on their hinder 

 margin. 2521. riAVOci.NERErs. 

 aa. First joint of antenme similar in the sexes and not in either sex longer 

 than the next two; second joint in both sexes not longer than third; 

 length 1.V23 mm. 2522. ijimacvlata. 



251!) (SOGO). MAcnoBA.sis torsa Lee, Proc. Phil. Acad. Nat. Sci., \l. 1S.5.S, 

 343. 



Elongate, slender. Black, sparsely clothed with short, grayish pubes- 

 cence; antenna? and legs black. Thorax slightly broader than long, sides 

 nearly parallel, curved at apex, median line iinpressMl. Elytra subparallel. 

 more or less pruinose, moderately punctured. Male with second joint of 

 antenna; cylindrical, compressed, and with first joint of front tarsi shorter 

 than second, narrcjw at base and fnore or less dilated. Female with second 

 joint of antenna; slightly longer than third. Lcngtli 11-15 mm. 



Crawford County ; rare. June IT. Known heretofore only from 

 Texas. Easily distinguished from unicnJor by the contorted first 

 joint of male antenna;. 



