REPORT ON THE PTEROPODA. 
47 
2. Subgenus Hyalocylix. 
Creseis striata, Rang. 
3. Subgenus Styliola. 
Cleodora subula, Quoy and Gaimard. 
4. Subgenus Clio, s. str. 
Balantium politum, Craven, MS. 
Cleodora andrese, Boas. 
Cleodora balantium, Rang. 
Hylasa australis, d’Orbigny. 
Cleodora sulcata, Pfeffer. 
Clio pyramidata, Linne. 
Hyalsea cuspidata, Bose. 
The four sections may be distinguished as follows : — 
I. Shell without lateral keels. 
1. Shell without dorsal longitudinal groove. 
A. Shell with a circular section, . . . .1. Creseis. 
B. Shell flattened dorso-ventrally, with transverse grooves over 
its entire length, . . . . .2. Hyalocylix. 
2. Shell with a dorsal longitudinal groove, . . . .3. Styliola. 
II. Shell with lateral keels, . . . . . . .4. Clio, including Balantium. 
Subgenus Creseis, 1 Rang (s. str.). 
1828. Creseis, Rang, Notice sur quelques Mollusques nouveaux appartenant au genre Cleodora, 
&c., Ann. d. Sci. Nat., s6r. 1, t. xiii. p. 302. 
Styliola, Auctorum, non Lesueur. 
Characters and Description. — Shell elongated, of conical form, with a circular 
transverse section, with a smooth surface on its initial portion at least, with the 
embryonic portion not marked off by a deep constriction, with a rounded apex. 
Animal with the left tentacle very rudimentary, the fin exhibiting a small narrow 
projecting lobe on the proximal half of the dorsal (anterior) margin, the opening of the 
mantle as broad as that of the shell. 
1 Mythological name. 
