60 



Cnodalon, Ijat. 



Where, from the fifth joint, the antennae are strongly compressed 

 and serrated, and where the head is much narrower than the thorax*. 

 Campsia, Lepel. and Serv. — Camaru, Id. 



Where the antennae, from the sixth joint, are slightly serrated, 

 and the head is as wide as the posterior margin of the thorax. The 

 body is proportionally longer and less convex, and the thorax wider 

 posteriorly f . 



In all the other Helopii, the mesosternum presents no remarkable 

 emargination, and the posterior extremity of the praesternum is not 

 extended into a point. 



Here the body is sometimes ovoid or oval, and at others more 

 oblong but narrowed at both ends ; it is never cylindrical or linear, 

 nor nmch flattened. Certain subgenera have been formed with He- 

 lopii, which approach the first in their strongly inflated body, which 

 is gibbous posteriorly. 



Those, in which the body is almost ovoid or short, and the thorax 

 transversal, plane or simply curved, compose the following sub- 

 genera. 



Spheniscus, Kirhy. 



Easily mistaken at the first glance for Erotylus, and in which, as- 

 in the preceding subgenera, the inner side of the last joints of the 

 antennae are dilated like the teeth of a saw, and the thorax is plane :{:. 



Acanthopus, Meg. Dej. 



Shorter and rounder than the Insects of the preceding subgejmsv 

 with simple antennae terminated by a larger and ovoid joint ; the 

 anterior thighs inflated and dentated, at least in one of the sexesy and 

 the tibiae almost linear with very short spurs, or almost none ; ante- 

 rior tibiae arcuated §. 



Amarygmus, Dalm. — Cnodalon, Helops, Chrysomela, Fab. 



Allied to Acanthopus, with simple but filiform antennae, and the 

 anterior thighs neither inflated nor dentated. All the tibiae are 

 straight and terminated by very apparent spurs ||. 



* Lat., Gener. Crust, et Insect, II, p. 182, and I, x, 7, 



f Encyc. Method., article Sphenisque. Messrs. Lepeletier and Serville give but 

 ten joints to the antennae of the Camarice, a character which would (Hstinguish them 

 from the other Helopii : but we have distinctly seen eleven in various Helopii from 

 Brazil, which appear to us closely allied to the C. nitida, quoted by them. Until we 

 can verify this anomaly in the individuals examined by those gentlemen, we think it 

 best to unite the two subgenera. Besides the Cnodalon irmratum of Germar, 

 quoted in this article, refer the Toxicum geniculatum and nigripes, ejusd., to the same 

 subgenus, 



X Spheniscus eryfoloides, Kirb. Lin, Trans., XII, xxii, 4 ; Encyc. Method,, article 

 Sphenisque. The Helopii suturalis and geniculatus of Germar form the passage from 

 this subgenus to Helops proper, 



§ Helops dentipes, Panz., Ross.; — Helops dentipes, Fab., another species, but 

 from the East Indies, 



II Dalm., Anal. Entom., p. 60. The Helops ater, Fab., should also be referred 

 to this subgenus. 



