58 SMITHSONIAlN MISCELLANEOUS COLLECTIONS VOL. 89 



CYNEDESMUS Cook 



This genus was erected to acconimodate a species from Grand 

 Canary, and later Cryptodesmus onmmcntatiis Karsch, from Cuba, 

 was added to it. Several West Indian species described under Treseo- 

 lobus by Chamberlin were reallocated by him in Cynedcsmus, but it 

 now appears that none of them belongs in this genus. His assumption 

 that Lophodesrnus Pocock is a synonym of this genus does not appear 

 justified after a careful review of the characters of the two genera. 

 The statement that no description of the type of Cynedcsmus has 

 been published is erroneous, as C. fonnicola was described in the 

 Proceedings of the Academy of Natural Sciences of Philadelphia, 

 1896, page 267. 



One difiference between Lophodesmiis and Cynedesmus is that the 

 outer margins of the keels of segments 3 to 19 inclusive are bilobed in 

 Lophodesmus, whereas in Cynedesmus some of the keels have three 

 or even four distinct lobes. The dorsal tuberculation in both genera 

 is of specific rather than generic value, for in each genus there are 

 species with two dorsal rows of large tubercles, and others have four 

 rows. In Lophodesmus the apical structure of each gonopod is en- 

 closed within the hollowed, hemispherical basal joint, whereas in 

 Cynedesmus the basal joint is smaller and the apical structure is less 

 crassate and rises above the base. 



CYNEDESMUS SIMPLEX;, n. sp. 



A single male was collected about 70 kilometers from Paramaribo, 

 Dutch Guiana, March 3, 1932, beside the railway to the Cable Station. 



Diagnosis. — The smaller size differentiates this species from the 

 others. None of the nonporiferous segments after the first has more 

 than three lobes on the keels, and the keels of the penultimate segment 

 are reduced in size and without sulci forming lateral lobes as on the 

 other segments. 



Description. — Length 5 mm, width .8 mm. 



Head with the apex of the vertex smooth, but the anterior part is 

 coarsely and irregularly granular to the upper limits of the antennal 

 sockets. Antennae with joint 5 longest and broadest. 



First segment with 10 scallops of equal size along the front margin ; 

 surface of the disk with 10 high, rounded tubercles arranged in a 

 transverse ellipse, the rest of the surface somewhat granular. 



Ensuing nonporiferous segments to segment 17 with the lateral 

 keels 3-lobed ; on segment 18 the lobes are indistinct, and the keels of 

 segment 19 are small and without any semblance of lobes. Keels of 



