THE ANT-LOVING BEETLES. 329 



It. Head large, truncate; antcnn;e very remote; first dorsal 

 of abdomen with distinct basal eariiue. 



XVII. EUPLECTUS. 



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

 rowed; antenna? less distant; abdomen without basal 

 carince. THESIASTES. 



g<j. Thorax without a diseal impression; elytra without discal 

 stria?. BIBLOPI.ECTI s. 



//. Prostermnn finely but distinctly carinate throughout the mid- 

 dle of its length; thorax with a small, subapical impression, 

 its basal fovea? connected by a transverse sulev ; antenna- 

 less widely separated, the tenth joint larger than usual. 



TIIESIUM. 



ee. Antenna 1 club consisting almost entirely of the larg > abrupt ter- 

 minal joint; thorax without discal impressions. 

 /. Ninth and tenth antennal joints very shoi't. distinctly trans- 

 verse. 



./'. Elytra with a subhumeral t'ovea 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 stria?, but with an elongate basal impression. 

 7r. Firs* dorsal segment of abdomen much elongated and with- 

 out trace of a median impression. 



XVIII. TRIMIOMELBA. 



kk. First dorsal shorter, equal to second. XIX. MELBA. 



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



with a discal stria and with two basal fovea? but without 



subhumeral fovea; sulcus of thorax not continued down the 



flanks but ending in small enlargements near the margin. 



TBIMIOPLECTUS. 



Rafoinis tolulcc Lee., dark brown, polished, clothed with long, 

 dense pubescence, antenna 1 and legs yellowish, length 2.1 mm., oc- 

 curs rarely near Cincinnati. 



XV". RHEXiusLec. 1849. (Gr., "I break.") 



Head and thorax each wider than long; tarsi with two unequal 

 claws; antenna 1 elbowed. One of the three species occurs in 1 1n- 

 State. 



(>!'.'! (1!>f>7). IJiiKxirs i.xsc'i'M'Ti's I.ec., Host. Joiirn. Nat. Hist., VI. IMU. 



103. 



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

 hairs. Head twice as wide as long, base truncate, front rounded, concave 

 and with three fovea?; occiput carinate. Antenna? reaching base of thorax, 

 joints 3 to 8 transverse, nearly equal; ninth twice as wide as third; tenth 



