NATICA. 31 



The late Dr. J. Gwyn Jeffreys identified this with N. affinis, 

 Grael. Mr. Verrill in reviewing Dr. Jeffrey's paper (Am. Jour. 

 Sci., 3 ser., v, 472), dissents from this consolidation, because 

 Nerita affinis, Gmel., is described as having a nacreous interior, 

 as inhabiting New Zealand, and is placed in the umbilicated 

 section of the genus. An inspection of the S}~st. Nat. of Gmelin 

 shows that in the last particular only is Verrill correct, no 

 silvery interior is mentioned, the habitat is said to be northern 

 seas and a reference is made to the Zool. Danica, prodr. of 

 Miiller. Still, the uncertainty of an unfigured species, insuf- 

 ficiently described, and the fact that it is, whether correctly or 

 not, placed among umbilicated species, forbid the use of the 

 name a-ffmin for the species. 



The synonyms are N. consolidates, Couth, (fig. 67), a southern 

 and smaller form, occurring as far southward as Massachusetts ; 

 N. septentrionalis, Beck (fig. 69), Greenland; probably N. russa, 

 Gould, Arctic Ocean ; N. operculata, Jeffreys (fig. 73), Japan. 



N. occlusa, S. Wood, a Crag fossil of England, has been 

 referred to this species ; I think it distinct, as the spire is much 

 more elevated and the whorls more convex. 



Var. VITTATA, Jeffreys. 



Spire more elevated, body-whorl with two purplish bands, one 

 of them showing on the penultimate whorl. 



Greenland. 



This will perhaps prove distinct ; I should think it, from the 

 description, more nearly allied to the fossil N. occlusa. 



Var. IANTHOSTOMA, Desh. Fig. 68; PL 19, fig. 89. 



Yellowish brown, irregularly white zoned, apex blackish; 

 interior purplish. Length, 2 inches. 



Kamtscliatka, Northern Japan. 

 N. IMPERVIA, Phil. PI. 9, fig. 60. 



Oval, with spire very short, rather solid, white, umbilicus 

 completely filled with callus. Length, 10 mill. 



Straits of Magellan. 

 N. PUSILLA, Say. PI. 21, fig. 6. 



Cinereous, or yellowish white, with sometimes one or two 

 obsolete bands ; columella callous nearly closing the umbilicus, 



