GRANDIDIKRIA IO61. 



Unio (Graudidieria) tsadioniis von- Martens, S. B. Ges, 



Naturf., 1903, p. 8. 



"At the first glance, this species reminds one of the species 

 of Tanganyika, especially Unio burtoni Woodw., by reason 

 of the greatly swollen upper portion of the shell, the general 

 outline and the brilliancy of the nacre, but the sculpture is a 

 little weaker, as are also the anterior teeth. 



No similar species is known to me from the Nile. One 

 specimen in the Berlin Museum received in about 1841 from 

 Captain Mion from Senegal, resembling U. gabonensis Kust., 

 has a certain likeness in size and inflation, but is decidedly 

 nearer Unio ccgypticits and niloticus Fer., (group Pharaonia 

 Bgt.), owing to the thin shell, the more central beaks, the very 

 thin cardinal teeth and the less brilliancy of the nacre, than our 

 species from Lake Tsad." 



Grandidieria cheeneuxi Neuville and Anthony. 



"Shell elongated, much longer than high, rounded before, 

 slightly pointed behind, posterior ridge slightly angulated ; 

 concentrically striate in the central part of the disk near the 

 margin and on the dorsal slope, slightly plicate above and at 

 the umbones ; cardinal teeth minute ; anterior lamella rather 

 thick ; posterior elongate. 



Length 28, height 18 mm." (Neuville and Anthony). 



Type locality, Lake Rodolphe. 

 Unio (Grandidieria) chefncuxi Neuvii,i,e and Anthony, Bull. 



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



1906. p. 410, pi. 12. 



"This species is specially distinguished by the restriction to 

 the beaks of the characteristic plications and its elongated 

 form. It resembles, perhaps, Unio acuminatus Ad." 



The following are unfigured species of Grandidieria: 

 G. rotundata Bourguignat, Not. Prod., 1885, p. 98. 

 G. mira Bourguignat, Not. Prod., 1885, p. 96. 

 G. incarnata Bourguignat, Moll. Gir., 1885, p. loi. 

 G. elongata Bourguignat, Moll. Gir., 1885, p. 14. 



