1887.] NATURAL SCIENCES OF PHILADELPHIA. 153 



Realia parvula, PfeiiFer, Mon. Pneum., iii, p. 213. 



Assiminea lucida, Pease, Jour, de Conch., 1869, p. 166, pi. 7, fig. 

 10 ; Proc. Zool. Soc, 1871, p. 476. 



Assiminea ovata, "Pease" Schmeltz, Cat. Mus. Godefi"., v, p. 103. 



Hydrocena pygmcea, Gassies, Jour, de Conch., 1867, p. 63. 



Assiminea pygmcea, Pease, Jour, de Conch., 1869, p. 165. 



? Realia pygmcea, Pfeiffer, Mon. Pneum., iv, p. 214. 



Hydrocena similis, Baird, in Cruise of the Curacoa. 



This species is distributed throughout all the groups from the 

 Paumotu's to the Viti Islands and New Caledonia. They are found 

 beneath decaying leaves, under stones and dead wood. 



It may be recognized by its small size (21 to 4 mill, long), smooth, 

 shining surface, ovate-conical form, light or dark corneous color ; 

 rarely with a faint transverse band on the last whorl. 



11 



