19t6, | H. B. Preston: South Indian Mollusca. 33 
Septaria crepidularia, Lamarck. 
Anim. s. Vert., VI, 2, 1822. 
Cochin backwater, near Ernakulam (F. H. Gravely). 
Family TROCHIDAE. 
Solariella deliciosa, sp. n. 
Shell small, rather depressedly conic, pale brownish-green, 
somewhat iridescent above, 
highly so on the base; whorls 
4, carinately angled above the 
last volution also strongly 
carinate at the periphery, the 
upper carination being tuber- 
cled throughout, sculptured 
with very minute and closely- 
set microscopic, oblique, trans- 
verse striae; suture impressed ; 
umbilicus ornamented round Fics. 10, 10a, 106.—Solaviella delictosa, 
its margin with a broad ridge sp. n. X 6. 
crossed by regular transverse 
costulae, moderately wide; columella margin rather sharply 
curved, outwardly expanded above into a white wing-like projec- 
tion ; labrum acute, sharply angled at the base and at the point of 
termination of the peripheral carina; aperture depressedly dia- 
mond shaped. 
Alt 15, diam. maj 3°25, diam min. 2°75 mm. 
Aperture: alt. 1 25, diam. i mm. 
Hab.—Ennur backwater, Madras. 

Family CycLOSTREMATIDAE. 
Cyclostrema micans, A. Ad. 
Proc. Zool. Soc. London, 1850, p. 44. 
Ennur backwater, Madras. 
Class LAMELLIBRANCHIATA. 
Order TETRABRANCHIATA, 
Suborder OSTRACEA. 
Family OSTREIDAE. 
Ostrea madrasensis, sp. n. 
This species may be compared to O. virginica, Gmel. (= 
O. cana/ensis, Lk.) from the E Coast of N. America, it is however 
of a straighter form and thinner texture and is much more 
foliaceous externally, the left valve is more concave and the 
