350 1NSECTA. 



Rhipioera, Lat. Kirby. Ptyocerus, Hoff. Polytomus, Daim. 



The antennae flabelliform in both sexes, and composed of numer- 

 ous joints (from twenty to forty), but fewer in the females. 



This subgenus consists of five or six species, two of which 

 are from New Holland, and the remainder from America(l). 



The three first joints of the tarsi in the two following subgenera 

 are in the form of a reversed heart, and have no membranous pro- 

 longation underneath; the fourth is deeply bilobate; the last, but 

 slightly elongated, exhibits no projecting and silky appendage be- 

 tween its crotchets. The antennae are filiform, simple, or at most 

 pectinated, and never consist of more than eleven joints. 



Ptilodactyla, Illig. Pyrochroa, De Geer. 



Distinguished by the semi-pectinated, or serrated antennae of the 

 males. 



The species of this subgenus are peculiar to America(2). 



Dascillus, Lat. Atopa, Fab. 



Only differs from Ptilodactyla in the antennae, which are simple 

 in both sexes(3). 



The remaining Cebrionites have small mandibles which project 

 but little, or not at all, beyond the labrum, a generally soft and al- 

 most hemispherical or ovoid body, and palpi terminating in a point. 

 The antennae are simple, or but slightly dentated. The posterior 

 legs of several are fitted for leaping. They live on aquatic plants. 



In these, the penultimate joint of the tarsi is bilobate. The second 

 and third of the antennae are shorter than the fourth. 



Elodes, Lat. Cyphon, Fab. Dej. 



The posterior thighs differing but little in thickness from those 

 of the preceding subgenus(4). 



(1) Rhipicera marginatu, Lat., Cuv., Reg-n. Anim. Ill; Kirby, Lin. Trans., XII, 

 xxi, 3; Polytomus marginatus, Dalm., Anal. Entom. p. 22; P. femorahis, Id. lb. 

 21: P- mystacinus, Id. lb. 22; Hispa mystacina, Fab.; Drur. Ins. Ill, viii, 7. I 

 have seen another species in the collection of Count Dejean, entirely fulvous, 

 sent to him from America by Major Le Conte. 



(2) Ptylodactyla elaterina, Illig'.; Pyrochroa nitida, De Geer, Ins., V, xiii, 6 17. 



(3) Atopa cervina, Fab.; A. cinerea, var , Id.; Piinus iestaceo-villosus, De Geer, 

 IV, ix, 8; Cistela cervina, Oliv., Col., Ill, 54, 1, 2, a, 



(4) The first division of Ctphon, Fab. 



