41 
Shell rather solid, subopake, smooth, strongly concentrically 
wrinkled, longitudinally obsoletelv substriated; posterior side acu¬ 
minated, subtruncated ; dorsal margin posteriorly sloping; spoon¬ 
shaped process thick and wide; ventral margin strongly arcuated. 
Hab. Ceylon, on the sands. (Mus. Cuming.) 
Anatinella dilatata, Adams. A . testa tenui, fragili, concen- 
trice corrugatd, longitudinaliter striata, latere postico dilatato , 
oblique valde tvuncato, margine dorsalipostice horizontali recto , 
processu cochleariformi parvo tenui , dentibus cardinalibus valde 
divergentibns ; margine ventrali arcuato. 
Hab. -? 
Shell thin, fragile, concentrically wrinkled, longitudinally striated ; 
posterior side dilated, obliquely strongly truncated; dorsal margin 
posteriorly horizontal and straight; spoonshaped process small, thin ; 
cardinal teeth greatly diverging, ventral margin arcuated. 
Hab. Puteao, Philippines, on sand-banks, at low water; H. C. 
(Mus. Cuming.) 
Anatinella ventricosa, Adams. A. testa tenui , ventricosa, 
semipellucidd, concentrice corrugatd , longitudinaliter conspicue 
striata', striis elevatiusculis, latere postico rotundato ; margine 
dorsali postice declivi; processu cochleariformi tenui, angusto ; 
margine ventrali leviter arcuato. 
Hab. -? 
Shell thin, ventricose, semipellucid, concentrically wrinkled, lon¬ 
gitudinally conspicuously striated, striae rather elevated, posterior 
side rounded, dorsal margin posteriorly sloping ; spoonshaped process 
thin, narrow, ventral margin slightly arcuated. 
Hab. Puteao, Philippines, on sand-banks, at low water; H. C. 
(Mus. Cuming.) 
February 26, 1850. 
W. Spence, Esq., F.R.S., in the Chair. 
The following paper was read 
1. Monographs of Cyclostrema, Marryat, and Separatista, 
Gray ; two genera of Gasteropodous Mollusks. By 
Arthur Adams, B.N., F.L.S. etc. 
Cyclostrema, Marryat. 
Animal ignotum. Operculum - ? Testa depressa, perspectivo- 
umbilicata ; apertura circularis. 
Shell depressed; aperture circular ; umbilicus very large, with the 
volutions of the whorls visible within it. 
Cyclostrema cancellata, Marryat. C. testd albcl, lineis lon- 
gitudinalibus et transversis elevatis clecussantibus hide cancel - 
