PTEROPODA. 205 



Cleodora, Peron and Lesueiu-. 



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



Type, C. pyramidata, PI. XIV. fig. 33. 



Shell pyramidal, 3 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 gill, the heart, and other organs are 

 visible through the pellucid shell. In C. curvata and pellucida {Pleuropiis, 

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



Distr. 12 sp. Atlantic, Medit. Indian Ocean, Pacific, C. Horn. 



Fossil. Miocene — . Brit. (C. infundibulum. Crag.) 



Sul-gemis. Creseis, Eang. (Styhola, Lesuem-). C. aciculata, PI. XIV. 

 fig. 34. Slender, conical, pointed, straight or curved. Pins rather narrow, 

 truncate, with small tentacles projecting from their dorsal edges, and rudi- 

 ments of the mesojwdium 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. Distr. 5 sp. (like Cleodora.) 

 CuviERiA, Rang.* 



Dedicated to Baron Cuvier. Type, C. columnella. Rang, PI. XIV. fig. 35. 



iS^g// 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. 



Distr. 4 sp. Atlantic, India, Australia. 



Fossil 1 sp. (C. Astesana, Rang.) Fliocene, Turin. 



Siib-yenus, Vayinella, Daud. V. depressa, PI. XIV. fig. 36. 5/?^/^ oblong, 

 with a pointed apex; aperture contracted, transverse. Fossil, 1 sp. Miocene. 

 Bordeaux, Turin. 



Theca, Morris. 1845. 



Type, T. lanceolata. Syn. Creseis, Porbes.f Pugiunculus, Barr. 



Shell straight, conical, tapering to a point, back flattened, aperture 

 trigonal. Lon. 1-8 inches. 



Fossil, 6 sp. Silurian. N. America, Brit., New South Wales. 

 Pterotheca, Salter. 



Type, P. transversa, Portlock, 3 sp. L. Silurian ; Ireland, Wales, Canada. 



Shell bi-lobcd, transversely oval, with a dorsal keel projecting slightly at 

 each end ; ventral plate small triangular. 



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

 of a pteropod, since ascertained to have been a Cuvieria. 



t Creseis Sedgwicki, Forbes, is an orthoceras with very thin septa, belonging to the 

 same group with {Conularia) teres, Sby. TentaciiUtes, Schl. is anellidous. {Salter.) 



