NO. 1205. SYNOPSIS OF THE NAIADES SIMPSON. 901 



SPATHA DIVARICATA von Martens. 



* Spatha (liraricata vox MARTENS, Beach., 1897, p. 250, pi. vn, fig. 15. 

 Lake Victoria; Nyanza. 



Subgenus MONCETIA Bourgnignat. 1885. 

 (Type, Mo-n eel i a anceyi BonraigBSt) 



Shell long elliptical, inequilateral, compressed, thick, somber-colored; 

 beaks compressed, smooth, sharp; hinge with a tubercular eminence 

 near the beak of the right valve, with two internal ligaments and three 

 groups of muscular impressions (Bourguignat). 1 



Animal unknown. 



SPATHA ANCEYI Bourguignat. 



* Moticeiia anceyi BOURGUIGNAT, Esp. Onk., 1885, p. 34; * Icon. Mai., 1888, pi. xxx, 



fig. 1. * vox MAHTEXS, Beach., 1-97, p. 258. 



* Moncetia joulerti BOURGUIGNAT Un. et Ir., 1886, p. 63; *lcon. Mai., 1888, pi. 



xxx, fig 4. 



Lake Tanganyika. 



SPATHA MONIETI Bourguignat. 



* Moncetia monieti BOURGUIGNAT, Un. et Ir., 1886, p. 61; * Icon. Mai., 1888, pi. 



xxx, fig. 7. 



* Moncetia rochebruneana BOURGUIGNAT, Nouv. Mai., 1886, p. 62; *Icon. Mai., 



1888, pi. xxx, fig. 8. 



Lake Tanganyika. 



SPATHA LAVIGERINA Bourguignat. 



* Moncetia lavigerina BOURGUIGNAT, Nonv. Mai., 1886, p. 60; * Icon. Mai., 1888, pi. 



xxx, fig. 6. 



* Moncetia bridoiui BOI'IHJUIGXAT, Un. et Ir., 1886, p. 65; *Icon. Mai., 1888, pi. 



xxx, fig. 5. 



Lake Tanganyika. 



Subgenus ASPATHARIA Bourguignat, 1885. 

 (Type, Margaritana rignoniana Bernard!.) 



Shell elongated rhomboid, somewhat compressed, with a full, rounded 

 posterior ridge, from which curved rows of fine, broken corrugations 

 radiate; epidermis dark olive , wrinkled, rayless; beak sculpture not 

 seen; hinge with a low, slightly elevated ridge in the left valve in front 

 of the beak; dorsal scars small; nacre lurid, bluish-green. Animal 

 unknown. 



'This may be a distinct genus, though its characters seem to agree fairly well in 

 most respects with those of Spatha. Bourguignat doesuot describe the muscle scars 

 or tell anything of the nacre. 



