OTIDRIIYNCIIIDAE. 449 



supcM-ior and conversely. None of our genera show a lateral form 

 ol' serobe such as seen in Oinias or Liclienopliagus. 



The occurrence of short fixed spurs to the hind tibia; in addi- 

 tion to the niucro, and at all evenls entirel}^ independently of it, 

 is noticed here. In one genus their occurrence appears to be 

 sexual, in others it cannot be so referred. 



The occurrence of scaly tips to the hind tibiae does not appear, 

 from descriptions, in any foreign genus of the group. Those in 

 our fauna might form a distinct group from the Periteli, and 

 would have been so constituted, were it not that Liclienophagus 

 occupies an intermediate place by the groove surrounding the 

 eyes and by the entirely glabrous tips of the hind tibia?. It is 

 also to be regretted that one of our species only appears to be 

 congeneric with any previously described. 



With the exception of one Geoderces from Canada, and one 

 Rhypodes from Colorado, the species of the preceding genera 

 belong to the Pacific fauna. 



Gronp IV.— Trachyphloei. 



AntennjB moderate, scape attaining at most the margin of the 

 thorax, usually the posterior margin of the eyes; funicle 7-jointed, 

 joints 1-2 longer than the others, joints 3-7 moniliform ; clul) 

 short, oval. Claws free. 



Although composed of species differing considerably in their 

 general aspect from those of the preceding group, no sharplv- 

 defined characters are found by which to distinguish the two. 

 The antennae are always less elongate, the scape long, feebl}'- 

 arcuate and slightly thicker to the tip, attains the thorax; the 

 funicle not longer than the scape, has the outer joints short, round, 

 and moniliform. 



The following genera occur in our fauna: — 



Metathoracic side pieces entirely coiioealed ; eyes with distinct orbital 



groove ; 



Scrobes superior, very short -and deep, not reaoliing tli<> eves ; anterior 



and middle tibifp feebly nuicronate. Cercopeus. 



Scrobes lateral, long, passing directly backwards and includinu the eyes : 



tibise strongly mncronate. Chaetechtis. 



Metathoracic side pieces visil)le ; sntnre at least moderately distinct ; 



Kyes with distinct orbital groove ; rostrum deeply transversely impressed 



at l>ase. Trachyphlceus. 



he species, one of each genus, occur in the Atlantic States. 

 29 



