GRAXDIDIERIA IO57 



Grandidieria rothschildi Neuville and Anthony. 



"Shell subrotund, slig"htly longer than high, rounded in 

 front, slightly carinated and scarcely pointed posteriorly ; con- 

 centrically striate along the margin, above, at the umbones, 

 in the centre of the disk and on the posterior slope strongly 

 plicate ; cardinal teeth usually small ; anterior lamella thick 

 and plicate ; posterior oblong. 



Length 27, height 20 mm." (N. & A.). 



Type locality, Lake Rodolphe. 

 Unio (Grandidieria) rothschildi Nruvii.le and Anthony^ 



Bull. Mus. Hist. Nat., 1906, p. 409; Bull. Soc. Philom., (9;, 



Vin, 1906, p. 409, pi. 12. 



"This species, which is distinguished by its very strong, 

 bilateral inflation, belongs to the group of Unios from Tan- 

 ganyika that Bourguignat, relying on characters of very little 

 value, incorrectly thought should be referred to the family 

 Sphccriidcv and for which he established the genus Gran- 

 didieria. It is related, moreover, to certain types of Unios 

 from Lake Victoria, such as Unio acuminatiis x\dams and U. 

 grandidieri Bgt. It is. however, more closely allied to Unio 

 (Pareyssia) bakeri Adams or to Unio (Grandidieria) graznda 

 Bgt. Much resembling the former by its general form, it 

 is distinguished by its shorter contour and the more marked 

 accentuation of the folds, which extend more generally over 

 the surface than in that species. It differs from the second 

 (U. graznda Bgt.) by being more pointed posteriorly, less 

 height compared with the length and stronger plications." 



Grandidieria thomsoni (Smith). 



Shell small, irregularly ovate, subinflated, inequilateral ; 

 beaks only moderately full or high, zigzag-wrinkled, rather 

 pointed ; anterior end narrowed and rounded ; base quite full 

 at or just behind the middle ; from there to the posterior point 

 the outline is straight ; posterior ridge close to the dorsal out- 

 line, narrowly rounded, lightly curved, ending in a decided 

 point on the median line ; surface more or less covered with 



