462 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 40. 



margin; lateral margin slightly impressed and notched to form four 

 rounded lobes on poriferous segments, three lobes on other segments; 

 posterior corners of carinas narrower than the anterior, not produced 

 backward except on posterior segments. (See figs. 5 and 6.) 



Repugnatorial pores rather large, opening toward the side, near the 

 margin of the carina, just in front of the sinus between the third and 

 fourth lobes. 



Last segment rather broadly triangular, projecting far beyond the 

 small and slightly produced carinas of the penultimate segment. 

 (See fig. 6.) 



A NEW GENUS FROM ST. PAUL DE LOANDA. 



A report was published in 1893 on a small collection of myriapoda 

 obtained from the U. S. National Museum by Mr. Heli Chatelaine at 

 St. Paul de Loanda, West Africa. 1 The specimen to be described 

 below was not included when the others were sent to 

 me for identification, perhaps because it was broken 

 into so many pieces. It did not come to my atten- 

 tion until five or six years afterwards, when descrip- 

 tions and figures were prepared, to await another 

 long delay in publication. 



Though the antennas and most of the legs have 

 been lost, the structural characters of the segments 

 and of the copulatory apparatus show that the ani- 

 mal represents, not only a new generic type, but 

 one that is not closely related to any other hitherto 

 crepek. segments described. The habit is quite similar to that of the 

 other West African and American genera belonging 

 to the family Pterodesmidas, but the resemblance proves to be a 

 merely superficial analogy, another of the numerous approximations in 

 external characters between millipeds that belong to unrelated families. 

 Notwithstanding the flattened dorsum and the broad wing-like 

 carinas, the affinities of the new genus lie with the Stylodesmidas, 

 Hercodesmidas, Chytodesmidas, and other related families that have 

 the basal joint of the gonopods very large and hollowed out to con- 

 tain and conceal the much smaller and more complicated distal joint. 

 This feature seems to be diagnostic of a cosmopolitan natural group 

 often confused with the South American family Cryptodesmidas. 



In addition to the large clypeate basal joint of the gonopods, the 

 Stylodesmidas and their allies are characterized by the prominent 

 positions of the repugnatorial pores, which are borne on special 

 lobes, processes, or tubercles, whereas the pores of the Pterodesmidas, 

 though seldom or never really absent, as at first supposed, are ex- 



i Proc. U. S. Nat. Mus., vol. 16, 1893, p. 703. 



