278 INSECTA. 



differs from the latter in its tarsi, the hooks of which are simple. 

 The body also is flattened, as in the preceding and other neighbour- 

 ing subgenera, tolerably broad, with filiform palpi, unidentated 

 mentum and transverse labrum; the thorax is wider than the head, 

 and nearly semi-orbicular. 



But one species is known. 



The other Carabici of the same division with equally simple 

 hooks are removed from the preceding by the form of their head, 

 which is suddenly narrowed immediately after its origin, presenting 

 the appearance of a neck or rotula. 



First come those in which the tarsi of both sexes are identical, 

 sub-cylindrical or linear, and whose penultimate joint, at most, is 

 deeply notched or bilobate. 



Sometimes the exterior palpi are filiform or but slightly enlarged 

 at the end, with the last joint verging to an oval; the head has the 

 same form and becomes gradually narrowed behind the eyes. The 

 first joint of the antennae is always short or but slightly elongated. 

 The thorax is always narrow and elongated. The body is thick. 

 The emargination of the mentum has a central tooth. The ligula is 

 almost square, and its paraglossia are salient and pointed. 



Casnonia, Lat. Ophioncea, Klug. 



The thorax almost like a truncated cone, or a cylinder narrowed 

 anteriorly(l). 



Leptotrachelus, Lat. 



Thorax cylindrical, and without any sensible contraction ante- 

 riorly; elytra entire or not truncated; penultimate joint of the tarsi 

 bilobate(2). 



Odacantha, Payk. Fab. 



The same kind of thorax, but the elytra are truncated and the 

 joints of the tarsi entire. 



Odac. melanura, Fab.; Clairv., Entom. Helv. II, v; Hist. Nat. 

 des Coleop. d'Eur., II, x, 6. The type of the genus; three lines 



(1) See Entom. Brasil., of Kliig; the Spec. Gener., of Dej., I, p. 170; Hist. 

 Nat. des Coleop. d'Eur., fascic. II, vii, 6. The species figured C. cyunocephala 

 from the penultimate joint of the tarsi forms a particular division. It is found in 

 Bengal. All the others, the principal of which is the Mtelabus pensylvanicus, 

 Lw, belong to America and have all the joints of the tarsi entire. 



American species, C pensylvanica, rufipes. Am. Ed. 



(2) Odacantha dorsalis, Fab. 



