1916. | Hy, B, PRESTON : South Indian Mollusca. 35 
inner margins of both valves, as well as the muscular scars, are of 
a deep purplish-black colour. 
Long. 140, lat. 56°5 mm. 
Hab.—Ennur backwater, Madras. 
Placuna placenta, [innaeus. 
Syst. Nat. ed, 12, p. 1154 (as Anomza). 
Ennur backwater, Madras (a single very juvenile specimen). 
Suborder MYTILACEA. 
Family MyvTirtmDaAe. 
Modiola taprobanensis, Preston. 
Ann. Mag. Nat. Ast. ser. 8, XVI, p. 84. 
Ennur backwater, Madras. 
Suborder ARCACEA. 
Family ARCIDAE. 
Arca granosa, Lin. 
Syst. Nat. ed. 12, p. 1142. 
Ennur backwater, Madras. 
Arca (Fossularca) lactea, Lin. 
Sista Nataed.-12)spsE ELT. 
Ennur backwater, Madras. 
Suborder CONCHACEA. 
Family VENERIDAE. 
Meretrix casta, Chem. 
Conch. Cab. VI, p. 349, pl. xxxiii, fig. 346 (as Venus). 
Ennur backwater, Madras; Cochin backwater, near Er:na- 
kulam ; juvenile specimens (F'. H. Gravely). 
Meretrix ovum, Hanley. 
Proc. Zool. Soc. London, 1845, p. 21. 
Cochin backwater, near Ernakulam. 
Meretrix zonaria, Lamk. 
Anim. s. Vert. VI, p. 299. 
Ennur backwater, Madras; Cochin backwater, near Ernaku- 
lam (young specimens only from both localities). 
