PTEROPOBA. 351 



PI. XIT. , Fig. , 38. Animal globular, witb two simple oval fins. 

 Distribution^ 1 species. Off Newfoundland 



CY:MBtrLlA, Peron and Lesueur. 



Etymology, diminutive of cymha, a boat, 

 Type, C. proboscidea, PI. XIV., Pig. 39 (after Adams), 

 Shell cartilaginous, slipper-shaped, pointed in front, trun- 

 cated posteriorly ; apertiwe elongated, ventral. 



Animal with large rounded fins connected ventrally by an 

 elongated lobe ; mouth furnished with minute tentacles ; lingual 

 teeth 1.1.1 ; stomach muscular, armed with two sharp plates. 



Distribution, 3 species. Atlantic, Mediterranean, Indian 

 Ocean. 



TiEDEMAi^NiA, Chiaje. 



Tijpe, T. Neapolitana, PL XIT., Pig. 40. 



Named after Pr. Tiedemann. 



Animal naked, transparent, fins united, forming a large 

 rounded disk ; mouth central ; tentacles elongated, connate j 

 eye-tubercles minute. Larva shell-bearing. 



Distribution^ 3 species. Mediterranean, Australia. 



Family II. — Limacikid^. 



Shell minute, spiral, sometimes operculate. 



Animal with fins attached to the sides of the mouth, and 

 united ventrally by an operculigerous lobe ; mantle- cavity 

 opening dorsally ; excretory orifices on the right side, 



The shells of the true Umacinidce are sinistral, by which they 

 may be known from the fry of Atlanta, Carinaria, and most 

 other Gasteropods. 



LiMACiNA, Cuvier 



Mymolagy, Umacina, snail-like, 



Synonym, Spiratella, Bl. 



Example, L. antarctica (drawn by Dr. Joseph Hooker), 



ri. xiY., Pig. 41. 



Shell sub-globose, sinistrally spiral, umbilicated ; whorls 

 transversely striated; umbilicus margined ; no operculum. 



Animal with expanded fins, notched on their ventral margins ; 

 operculum lobe divided ; lingual teeth 1.1.1. 



Distribution, 2 species. Arctic and Antarctic Seas; gre- 

 garious. 



SPlRLa^is, Eydoux and Souleyet. 

 Example, S. bulimoides, PI. XIY., Pig. 42. 



