I 192 ORIENTAL UNIONID^ 



end slightly narrowed, obliquely cut away from the beaks to 

 near the base, narrowly rounded below ; surface radially and 

 concentrically sculptured so that it is retriculated throughout; 

 within there is a strong rib, which supports the cardinal teeth. 



Length 95, height at the beaks 36, at hinder end of ligament 

 39 mm. 



Kistna River, India. 

 Unio footei Thkobald, Jl. As. Soc. Beng., XLV, 1876, p. 187, 



pi. XIV, figs. 9, ga. 

 Arcidopsis footei Simpson, Syn.. 1900, p. 861. — Haas, Con. 



Cab., Unio, 1910, pi. xi, figs. 2-4. 



A remarkable form, which may not belong to the Unionid^ 

 at all. The beaks form an angle between the anterior end and 

 dorsum, the narrowly rounded anterior point below projecting 

 forward in an unusual manner. 



Unfortunately Theobald's Latin description of Unio footei 

 is not at all complete. No laterals are mentioned, and he says 

 nothing of the color of the epidermis or of the nacre. The 

 beaks were too much worn in his specimens to give any char- 

 acters. The shell resembles some of the Areas of the Barbatia 

 group. 



The following are indeterminate Oriental Unionidse : 

 Unio alficriauHS Bourguignat, Voy. Choa, 1885, p. 43. Choa, 



Central Africa. 

 Unio antiniloticus Bourguignat, Bull. Soc. Zool. Fr., XL. 



1880, 482, pi. XII, fig. 5. Senegal. 

 Unio ascia HanlKy, Biv. Shells, 1856, p. 385, pi. xxiii, fig. 20.. 



Penang. 

 Unio hridouxi Bourguignat, Un. & Ir. Tan.. 1886, p. 13. Lake 



Tanganyika. 

 Unio forscali Parreyss. Where described? Egypt. 

 Unio gihhns SpEngeer, Skriv. Selsk. Nat., IH, i793, P- 64. 



Tranquebar. 

 Unio gnillcnicti Bourguignat, Un. & Ir. Tan., 1886. p. 15. 



Lake Tanganyika. 

 Unio lianiyanns Bourguignat, Voy. Choa.. 1885, p. 42. Cen- 

 tral Ethiopia. 



