MUSEUM OF COMPARATIVE ZOOLOGY. 361 



Jaw smooth, wath median projection. 



Lingual membrane with tricuspid centrals and laterals, and aculeate, bifid, 

 marginals, in the typical species ; others vary. 



Ceylon. 



For figure of animal, jaw, and lingual dentition, see Humbert, Rev. et Mag., 

 1862, p. 428. 



Mariella, Gray (1855), is b)' some considered identical, and, if so, its name 

 will take precedence. Identical with this lust is Clypeidella, Val. ms., and 

 Clypeicella. Viquesnelia, Desh., is also considered identical. (F. Atlantica, 

 Mor., has the pulmonary orifice posterior.) 



Farmarion, Fischer. {Rigasia, Gray.) Animal limaciform, subcylindrical, 

 tapering behind : tentacles simple : mantle large, anterior, enclosing an internal 

 shell-plate, which is partially exposed by a posterior opening : distinct locomo- 

 tive disk ? longitudinal furrows above the margin of the foot and caudal mucus 

 pore, over which is a horn-shaped process : external anal and respiratory orifices 

 on the posterior right margin of mantle (see Von Martens's figure of P. [papil- 

 laris) : orifice of combined genital system ? 



Shell-plate internal, rudimentary, flat, with a side nucleus. 



Jaw smooth, with median projection. 



Lingual membrane with tricuspid centrals, bicuspid laterals, and aculeate, 

 bifid marginals. 



Java, India. 



For figure of animal, see Von Martens, Preuss. Ost. Asien ; of jaw and lin- 

 gual dentition, see Semper, Phil. Arch. 



Urocyclus, Gray. Animal limaciform, subcylindrical, blunt before, taper- 

 ing behind : tentacles simple : mantle small, anterior, with a posterior opening, 

 and concealing an internal shell-plate : longitudinal furrows above the margin 

 of the foot and caudal mucus pore : a distinct locomotive disk : external respi- 

 ratory and anal orifices on the right slightly anterior margin of the mantle : 

 orifice of combined generative organs behind and below right eye-peduncle. 



Shell-plate internal. 



Jaw smooth, without median projection. 



Lingual membrane with tricuspid centrals, bicuspid laterals, aculeate and 

 bifid marginals. 



Mozambique. 



For figure of animal, see Ann. Nat. Hist., [3,] XV., 1865, p. 331; of jaw and 

 lingual dentition, see Bull. Mus. Comp. Zool., ante, p. 333. 



Nearly allied to Parmarion ; seems only to diff"er by the position of the respi- 

 ratory orifice, and the want of a horn-shaped process to the caudal pore. 



Dendrolimaz, Heynem. Animal limaciform, subcylindrical, blunt before, 

 tapering behind : tentacles simple : mantle small, anterior, concealing an in- 

 ternal shell-plate, perforated posteriorly : longitudinal farrows above the mar- 

 gin of the foot ? a caudal mucus pore, with overhanging, horn-shaped process : 

 distinct locomotive disk : anal and respiratory orifices at anterior right edge of 



