﻿J202 psia'i><)si'.\riiA 



Genus i^SHUDOSPATHA Simpson, 1900. 



Spatha Smith, Pr. Zool. Soc. Lond., 1880, p. 350. 

 Burtonia IjOURCUiGxNAT, Moll. Fluv. Nyanza, 1883, p. 20. 

 Pseudospatha Simpson, Syn,, 1900, p. 577. — Germain, Arch. 



Zool. Exp. et Gen. (5), 1, i()09, p. 46. 



Shell compressed, thin, oblique, inequilateral, with a straight 

 dorsal line, which ends in a small wing in front and behind, 

 rounded and cut away at the anterior base, produced in the 

 post-basal region, gaping in front and behind, slightly twisted 

 on its axis and usually bent posteriorly to the right or left ; a 

 low, often double posterior ridge ends in a biangulate point 

 behind ; beaks compressed, the sculpture faint, irregular, con- 

 centric ridges, which continue over the shell, and at the beaks 

 sometimes become rather sharply pustulous, the glochidium 

 often remaining; epidermis yellowish-brown, sometimes deli- 

 cately rayed ; teeth rudimentary, one or more faint, compressed 

 pseudocardinals and a sing'le lateral in each valve ; muscle scars 

 irregular ; nacre coppery or purple, often rayed. Animal un- 

 known. 



Type, Spatha tanganyicens^is Smith. 



The shells of this group bear a striking resemblance to that 

 of Livnpsilis Icptodon, in form, texture, color, teeth and in 

 gaping in front and behind. While I know nothing whatever 

 of the anatomy, I feel positive that the species do not belong- 

 to the Midtilidcc, for such vestigial teeth as they possess are dis- 

 tinctly schizodont and not at all taxodont. The beak sculpture, 

 though sometimes nodulous, shows more or less plainly con- 

 centric ridges, and this would indicate that the genus belonged 

 to the Exolvanchicc. I believe that it is rather closely related 

 to Cf'.amberlainia, Pilsbryoconcha and Cristaria, and the fact 

 that all its species are found in Tropical Africa does not seem 

 to me to be any evidence against this, for the genera NodiUaria 

 and Parreysia are distributed over the two areas and the; Ano- 

 donta guillaini of Recluz, which is found in the Somali country 

 in Africa, appears to be most nearly related to forms of south- 

 eastern Asia, so that I have placed it in the genus Latnellidens. 



