NEOTROPICAL PLATYRHACID MILLIPEDS — HOFFMAN 27 



This list unfortunately omitted two species, N. nicaraguanus and 

 N. nigricaudus, both described by Chamberlin in 1922. Of the total 

 of eight species now accounted for, a key to seven was published by 

 Attems in 1938, omitting only the inadequately known alboalatus. 



My friend and colleague R. W. Lichtwardt recently sent for identi- 

 fication a platyrhacid from Panama that he had examined for eccrinid 

 fungi. This specimen represents an unnamed form of Nyssodesmus, 

 probably a distinct species, which I dedicate to the memory of the 

 distinguished myriapod specialist, Carl Graf Attems. 



Nyssodesmus attemsi, new species 



FiGUHE \d 



Holotype, male, USNM 2468, Puerto Armulles, Panama, collected 

 on August 5, 1952, by G. W. Martin. 



Diagnosis: A species of Nyssodesmus with obliterated dorsal 

 tuberculation, and with the apex of the gonopod tibiotarsus squarely 

 truncated instead of drawn out or rounded. 



Description: Length, about 80 mm., greatest width, 13.5 mm. 



Head capsule strongly sculptured; vertigial groove deep and 

 distinct, interantennal ridges high and polished, terminating abruptly 

 just above the first antenna! article; subantennal ridges tuberculate 

 to subcristate, subantennal swellings distinctly granular; lower half 

 of genae vertically striate. Labral setae about 9-9, clypeal setae 

 3-3, the outermost on each side remote from the other two; a pair 

 each of frontal, interantennal, and vertigial setae. Antennae rather 

 long and slender, reaching back to third segment; articles 2-5 sub- 

 equal in size, clavate, cyhndrical; 6 longer and less clavate; 2 not 

 exceeding apex of genae. 



Collum broadly subhexagonal, the anterior and posterior margins 

 subparallel across body, abruptly converging laterad to an acute 

 angle; surface of collum roughly granular with an elevated ridge 

 across the front edge and a slightly depressed area on each side of 

 the middle toward the lateral ends. Caudal margin with four or 

 five indistinct low tubercides; anterior margin without traces of 

 tuberculation. 



Tergites of segments 2-4 subsimilar in shape, much broader than 

 collum, their paranota directed cephalad, with an anterior marginal 

 ridge and with three or four low indistinct lateral marginal tubercules. 

 Surface of paranota roughly granular, surface of middorsum coriaceous. 

 The following segments with broader paranota that are more nearly 

 transverse; in going caudally the anterior margins are increasingly 

 swept back, the lateral teeth increase to five or six, and the caudo- 

 lateral angle increases to form a distinct produced and incurved spine 

 on segments 15-17. Simultaneously, the dorsal sculpture diminishes 



