468 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



transparent lateral margins of the anterior carinse of C. pusittus are 

 produced into distinct teeth, each with a large projecting bristle, 

 instead of rather obscurely and unevenly sinuate-dentate as in C. 

 olfersii. Posterior margins with fewer and less distinct teeth than 

 in C. olfersii. 



The segments of C. pusillus are distinctly convex in the middle, 

 and the adjacent tubercles of the anterior row run together to form 

 a transverse ridge. Neither of these features was noted in 0. olfersii, 

 the segments of which have three regular transverse rows of simple 

 granules, each provided with a short hair. 



Repugnatorial pores in C. pusillus located in distinct furrows that 

 separate the bases of the marginal teeth, in front of the first tooth 

 before the posterior corner. In C. olfersii there is no such distinct 

 development of the marginal teeth, and the pores are located on a 

 slight broad elevation, rather close to the margins of the segments. 



APOMUS, new genus. 



Such differences would seem to require the recognition of a distinct 

 genus, for which the name Apomus is proposed, with Apomus pusillus 

 (Attems) as the type. Though the specialization of the first segment 

 in Apomus is carried even farther than in Cryptodesmus, the gonopods 

 are distinctly of the same peculiar pattern as those of Pocock's 

 Peridontodesmus flagellatus from Guatemala. 



NOTES ON THE SOUTH AMERICAN GENUS CHONODESMUS. 



The genus Chonodesmus , based on Cryptodesmus alatus Peters, 

 from Bogota, Colombia, has been referred to the African family 

 Pterodesmidse on account of a very close approximation in the 

 form and ornamentation of the segments, and the location of the 

 repugnatorial pores in the anterior part of the carina. Nevertheless, 

 it is possible that Chonodesmus belongs to the true Cryptodesmidse 

 or to the Peridontodesmidse, if these groups are distinct. The situa- 

 tion of the repugnatorial pores at the side of a small elevation is much 

 as in Peridontodesmus and the gonopods are quite complicated, 

 much more so than those of any of the African genera of Peterodes- 

 midse. The first segment is much shorter than in Cryptodesmus and 

 Apomus, being less than one-third as long as broad, and the posterior 

 margin is nearly transverse, instead of being turned forward at the 

 sides. The following notes and figures were drawn from the type- 

 specimen in the Berlin Museum. 



CHONODESMUS ALATUS (Peters). 



Cryptodesmus alatus Peters, Monatsber. konigl. Akad. Wiss. Berlin, 1864, p. 621. 

 Chonodesmus alatus Cook, Brandtia, p. 23, June, 1896. 



Antennae rather short and robust, distinctly clavate; joints 5 and 

 6 subequal, much larger than the others; joint 2 only slightly longer 



