COLEOPTERA. 411 



FAMILY III. 



PLATYSOMA(l). 



Our third family of the Tetramera approaches the second, so far 

 as relates to the internal anatomy, the tarsi, and habits; but the an- 

 tennae are of equal thickness throughout, or more slender towards 

 the extremity. The mandibles are always salient, the ligula is bifid 

 or emarginated; the palpi are short, the body is depressed and elon- 

 gated, and the thorax almost square. These Insects are found 

 under the bark of trees, and may be reduced to a single genus, the 



Cucujus, Fab. 

 Where the antennx, much shorter than the body in several, are composed 

 of obconical or turbinifonn and almost granose joints, the first of which 

 is shorter than the head. 



There are two subgenera, Dendrophagua and Uleoiota. 



FAMILY IV. 



L0NGIC0RNES(2). 



Here, the under part of the three first joints of the tarsi is fur- 

 nished with a brush; the second and third are codiform; the fourth 

 is deeply bilobate, and there is a little nodule resembling a joint at 

 the base of the last. The ligula, placed on a short and transversal 

 mentum, is usually membranous, cordiform, emarginated or bifid, 

 corneous and forming the segment of a very short and transversal 

 circle in others. The antennae are filiform or setaceous, most com- 

 monly as long at least as the bodyj they are sometimes simple in 

 both sexes, and sometimes serrated, pectinated, or flabelliform in 

 the males. The eyes of a great many are reniform and surround 

 them at base. The thorax is trapezoidal or narrowed before, in 

 those where the eyes are rounded and entire, or but slightly emar- 

 ginated; even in this case the legs are long and slender, and the tarsi 

 elongated. 



As almost all their larvae live in the interior of trees, or under 

 their bark, they are destitute of feet, or have but very small ones. 



(1) Flat-bodied. (2) Long-homed. 



