492 COLEOPTERA OF NORTH AMERICA. 



side pieces of the nieso- and metasternuui are very large. The 

 ventral sutures are curved at the sides; the first segment is as 

 long as tlie metasternum, the second is shorter, third and fourth 

 together equal to the second ; fifth nearly as long as the first, 

 truncate, and impressed in the male. Legs slender, thighs slightly 

 clubbed, tibiffi obliquely fringed at the tip, terminal hook very 

 small at the inner angle. Tarsi with the third joint very broad, 

 bilobed; fourth joint small, with a single claw. 



Mononychus vulpeculus, iu the Atlantic States, is our sole 

 representative. 



Group II. — Coeliodes. 



In the species of this group the eyes are partially covered by 

 postocular lobes, when the head is deflexed, and the pectoral 

 groove extends into or beyond the mesosternum, the beak is long 

 and cylindrical. The side pieces of the nieso- and nietasternuni 

 are large and wide. The ventral sutures are curved, and the 

 first is as deeply impressed as the others; the second segment is 

 shorter than the first ; third and fourth still shorter, fifth nearly 

 as long as the first. The pygidium is perpendicularly deflexed, 

 marked with an elevated angulated line for the reception of the 

 tips of the elytra, in front of which it is carinated. The third 

 joint of the tarsi is very broad and bilobed, the fourth is as long 

 as the first, with two claws, which are cleft or toothed. 



The following genera are represented in our fauna: — 



Tibi?e flattened, toothed on the outer side. . 2, 



Tibije slender, not dilated nor grooved. 3. 



2. Pectoral groove extending to tlie metasternum. Craponius. 

 Pectoral groove not extending to the metasternum. Cnemogonus. 



3. Body broadly ovate, elytra suddenly wider. Coeliodes. 

 Body pyriform, elytra gradually wider. Acallodes. 



None of the species have been found on the Pacific slope. 



Ornup III.— Ceutorhynchi. 



The species of this grou)i are small, and of the broad ovate 

 form us.ual in the tribe. They differ from the preceding group 

 by the pectoral groove not- extending behind the front coxse, and 

 from the next group by the beak being long, slender, and curved; 

 usnallv about half the length of the body The eyes are small, 

 not prominent, and are partially concealed in repose by broad 



