PTEEOPODA. 349 



Cleodora, Peron and Lesueur. 



Synonyms, Clio, L. (part) not Miiller. Balantium, Leach MS. 



Type, 0. pyramidata, PL XIV., Fig. 33. 



Shell pjTamidal, 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 (r) 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 peUiicida [Pleuropus, Esch.) 

 the mantle is furnished with two long filaments on each side. 



Distrihution, 12 species. Atlantic, Mediterranean, Indian 

 Ocean, Pacific, Cape Horn. 



Fossil, 4 species. Miocene — . Britain. {C. infundihulum, 

 Crag.) 



Sub-genus. Creseis,'RaTig. (Styliola, Lesueur.) C. aciculata, 

 PI. XIV., Fig. 34. Slender, conical, pointed, straight, or curved. 

 Fins rather narrow, truncate, with small tentacles projecting 

 from their dorsal edges, and rudiments of the mesopodium on 

 their surface ; mantle-margin with a spiral process on the left 

 side. M. Eang states that he has seen these pteropods clustering 

 round floating seaweed. 



Distrihution, 6 species (like Cleodora). 



CxJViEEiA, Eang.* 



Dedicated to Baron Cuvier. 



Type, C. columneUa, Eang, PI. XIV., Fig. 35. 



Shell cylindrical, transparent ; aperture simple, transversely 

 ovate ; apex acute in the young, afterwards partitioned ofi", 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, Eang.) Pliocene, Turin. 



Sub-genm. Vaginella, Daud. V. depressa, PI. XIV., Fig. 36. 

 Shell oblong, with a pointed apex ; aperture contracted, trans- 

 verso. Fossil, 4 species. Miocene. Bordeaux, Turin. 



Theca, Morris. 1845. 

 Type, T. lanceolata. 



* Under the name of "triptere," MM. Quoy and Gaimard described the fragment 

 of a pterop.U, since ascertained to have been a Cuvier iu. 



