AFRICAN DIPLOPODA OF THE GEXUS PACHYBOLUS. 



By O. F. Cook, 



Custodian of Myiiapoda. 



Tliroughout tropical Africa from Seneganibia to the Congo and Zan- 

 zibar are to be found large, robust and heavily armored Spiroholi of 

 closely similar form and color pattern, being in life transversely banded 

 with vermilion, the bright color affecting the anterior part of the segmen- 

 tal rings nearly to the level of the repugnatorial pores. Such a species 

 was described from Sierra Leone as iipiroboius gigantcus^ by Porat, who 

 later reported and redescribed the same species from Liberia,^ in both 

 cases insisting upon its close relationship with Spiroholns crassicollis' 

 Peters from Mozambique. In 1893 Pocock ' placed this species, together 

 with llgulatns Voges mid simillimns^QW[)ort, as synouyms of pulviUatus 

 Newport, and adds : '• It is extremely common at Lagos.'' More recently 

 Poraf has adopted this synonymy and ad<led to it !::ipifoholi<s crassicol- 

 lis Peters, on the ground that it can no longer be kept separate, as a 

 trace of a marginal sulcus appears in West African forms, this being, 

 in his opinion, apparently the sole difference between the two species. 



In reality it will be necessar}' to revise this entire synonymy. Peters's 

 crasdcolHs is an animal probably generically different from any of the 

 forms in question, and the Lagos species, or at least the type of lignlatiis 

 Voges, is specitically distinct •from specimens from Kamerun, Togo, and 

 Seneganibia, and, moreover, these last are different from each other. 



The types of Newport's species were from the Gold Coast, and as the 

 Togo colony lies between the Cold Coast and Lagos the presence of the 

 same form in the latter places is rendered antecedently improbable, 

 though there is, of course, no reason why any locality sliould be limited 

 to one species, even though the material at hand does not show two 

 species from any of the regions mentioned. The individuals from each 

 locality appear to be constant in the features supposed to indicate spe- 

 cific distinctness, but the affinities are not geographical; thus the Togo 



1 (ElVcrs. Sk. Vet.-Aliad. FiirbaiuU., 1872, No. 5, p. 17. 

 -Ann. Soc. Ent. Belgique, 1888, XXXII, p. 246. 

 ^'Aim. and Mag. Nat. Hist., 1893, 6th ser., XI, p. 249. 



^ Bill. K. Sv. Yet. Ak. Ilandl., 1894, IV, No. 5, p. 59. " Spirobolus xmlcillatm '' is also 

 hi'ic reported from Kameruu. 



Proceedings U. S. National Museum, Vol. XXI— No. 1 168. 

 Proc. N. M. vol. xxi 42 657 



