UNIO.— Plate XXVI. 



The yellow-toothed Unio. Shell triangularly wedge- 

 shaped, thick, with the umboes protnineiit, anterior 

 side very short, rounded, posterior triangularly acu- 

 niinntcd, very dark brown. 



Benson, :MS. in Mus. Cumin-. 



Hab. ]5engal. 



A solid wedge-shaped shell, very triangular in lorni, 



with the umboes rather prominent. 



Species 132. (Mus. Cuming.) 



U.Mo -Egyptiacus. Un. testa transversim ovata, teiiui- 

 culd, concentrice rmli striatn, latere antiro compressi 



prodiicto, deinde rotundato, postico etiam compresae 

 prodiicto, latiusculo, yihboso; fuho-oUvaced, nigricante- 

 hrimneofiimatd. 



The Egyptian Unio. Shell transversely ovate, rather 

 thin, concentrically rudely striated, anterior side 

 compressly produced, then rounded, posterior side 

 also compressly produced, rather broad, gibbous ; 

 fulvous-olive, banded with dark-brown. 



Cah.liaid, Voy. a Meroe, vol. ii. pi. (U. f. <i, 7. 



Hob. River Nile, Egypt; Cailliaud. 



The chief peculiarity of this species is its produced 



compression on either side of the umboes along the hinge 



margin. 



