PTEROPODA. 349 
CLEODORA, Peron and Lesueur. 
Synonyms, Clio, L. (part) not Miler. Balantium, Leach MS. 
Type, C. pyramidata, Pl. XIV., Fig. 33. 
Shell pyramidal, three-sided, striated transversely ; ventral 
side flat, dorsal keeled; aperture simple, triangular, with the 
angles produced; apex acute. 
Animal with rudimentary eyes; tentacles obsolete ; mantle- 
margin with a siphonal (?) process; fins ample, united ventrally 
by a rounded lobe; lingual teeth 1.1.1. The transverse bars of 
the gills, the heart, and other organs are visible through the 
pellucid shell. In C. curvata and pellucida (Pleuropus, Esch.) 
the mantle is furnished with two long filaments on each side. 
Distribution, 12 species. Atlantic, Mediterranean, Indian 
Ocean, Pacific, Cape Horn. 
Fossil, 4 species. Miocene—. Britain. (C. infundibulum, 
Crag.) 
Sub-genus. Creseis, Rang. (Styliola, Lesueur.) C. aciculata, 
Pl. XIYV., Fig. 34. Slender, conical, pointed, straight, or curved. 
Fins rather narrow, truncate, with small tentacles projecting 
from their dorsal edges, and rudiments of the mesopodiwm on 
their surface; mantle-margin with a spiral process on the left 
side. M. Rang states that he has seen these pteropods clustering 
round floating seaweed. 
Distribution, 6 species (like Cleodora). 
CUVIERIA, Rang.* 
Dedicated to Baron Cuvier. 
Type, C. columnella, Rang, Pl. XIV., Fig. 35. 
Shell cylindrical, transparent; aperture simple, transversely 
ovate ; apex acute in the young, afterwards partitioned off, and 
usually deciduous. 
Animal with simple narrow fins, united ventrally by two small 
lobes; lingual teeth 1.1.1. 
Distribution, 4 species. Atlantic, India, Australia. 
Fossil, 1 species. (C. astesana, Rang.) Pliocene, Turin. 
Sub-genus. Vaginella, Daud. V. depressa, Pl. XIYV., Fig. 36. 
Shell oblong, with a pointed apex; aperture contracted, trans- 
verse. Jossil, 4 species. Miocene. Bordeaux, Turin. 
THEcA, Morris. 1845. 
Type, 'T. lanceolata. 
* Tnder the name of “ triptére,” MM. Quoy and Gaimard described the fragment 
of a pteropnd, since ascertained to have been a Cuvieria 
