THE ANT-LOVING BEETLES. 329 



ft. Head large, truncate ; anteimte very remote ; first dorsal 

 of abdomen with distinct basal carinse. 



XVII. EUPLBCTUS. 



hh. Head smaller, the front more abruptly and strongly nar- 

 rowed ; antennte less distant ; abdomen without basal 

 carince. Thesiastbs. 



gg. Thorax without a discal impression ; elytra without diseal 



stria?. BiBLOPLECTL'S. 



ff. rrosteruum finely but distinctly carinate throughout the mid- 

 dle of its length; thorax with .-i small, subapicnl imiiri'ssiim, 

 its l)asal f()ve;e connected by a transverse sulcu ; antenna' 

 less widely separated, the tenth joint larger than usual. 



Thesium. 

 ( c. Antennal club consisting almost entirely of the larg' abrupt ter- 

 minal .loint; thorax without discal impressions. 

 /. Xinth and tenth antennal .loints very short, disti:ictly trans- 

 verse. 

 j. Elytra with a subhumeral fovea from which an acutely ele- 

 vated carina extends to apex ; also with discal stria? reach- 

 ing to middle ; head never wider than thorax, the latter 

 with a large fovea on each side connected by a transverse 

 groove. AcTiUM. 



jj. Elytra without trace of a subhumeral fovea and without 

 discal strife, but with an elongate basal impression. 

 7,-. First dorsal segment of abdomen much elongated and with- 

 out trace of a median impression. 



XVIII. Teimiomelba. 



l-k. First dorsal shorter, equal to second. XIX. JIelba. 



//. Ninth and tenth antennal joints larger, less transverse; elytra 



with a discal stria and with two basal fovece but without 



subhumeral fovea ; sulcus of thorax not continued down the 



flanks but ending in small enlargements near the margin. 



TrIMIOPLI'X'TIS. 



Rafonus tohdcr Lee, dark brown, polished, clothed with long, 

 dense pubescence, antennae and legs yellowish, length 2.1 mm., oc- 

 curs rarely near Cincinnati. 



XV. Rhexius Lee. 3849. (Gr., "I break.") 



Head and thorax each wider than long; tarsi with two une(|ual 

 clatt'S; antenna,' ('llii)\ve(!. One of the tlii'ee species occurs in the 

 State. 



IVS', (I'.iriT). Khexius iivscuLPTrs Lee, ISost. Journ. Nat. Hist., \'l, 1840, 

 103. 

 Subcylindrical, deiiressed. Pale reddish-brown, clothed with short erect 

 hairs. Head twice as wide as long, base truncate, front rounded, coii<-ave 

 and with three fovea'; occiput carinate. Antennre reaching base of thorax, 

 joints '■^ to 8 transverse, nearly equal; ninth twice as wide as third; tenth 



