34 DR. GWYN JEFFREYS ON THE MOLLXJSCA OF THE [Jan. 20, 



Two dead specimens, one larger than the other, and apparently 

 full-grown. 



Closely resembling in the shape and spire N. immaculata of Totten, 

 a native of the eastern coasts of North America ; but in that species 

 the umbilicus is open and exposed. Query as to the scientific value 

 of this character, except in adult specimens ? 



13. Natica nana, Moller. 



N. nana, Moll. Ind. Moll. Gronl. p. 7. 



Lunatia nana, Gr. O. Sars, Moll. reg. arct. Norv. p. 1.59, t. 21. 

 f. 16, a, h. 



'Porcupine' Exp. 1869: St. The Minch. Two dead specimens. 



Distribution. Spitzbergen (Torell and ' Voringen ' Exp.), Vadso, 

 (G. 0. Sars), Greenland {Moller), New England (Verrill), G. St. 

 Lawrence (JT'hiteaves), Aleutian I. (Dall) ; 10-430 fms. 



Specimens from Spitzbergen and Greenland differ as to the relative 

 height or prominence of the spire ; hut the inner lip and umbilical 

 pad seem to offer constant characters. 



14. Natica josephinia, Risso. 



Neverita josepMnia, Risso, Eur. mer. p. 149. f. 43 (1826). 



'Porcupine' Exp. 1870: Med. St. 50, 55, Benzert Road, Ad- 

 venture Bank. 



Distribution. Cadiz {Paz, f. Hidalgo), and throughout the 

 Mediterranean and Adriatic; 4-10 fms. 



Fossil. Miocene, Pliocene, and Post-tertiary : from Belgium to 

 Sicily and the Morea, Rhodes and Cyprus. 



Natica alia of Marcel de Serres, 1829. 



The young of this, as well as of the next species, has its peculiar 

 and characteristic inner lip or callus. 



C. Operculum calcareous. Nacca, Risso. 

 15. Natica operculata ', Jeffreys. (Plate IV. figs. 7, 7 a.) 



Shell globular, thick, opaque, glossy : sculpture, merely lines of 

 growth : colour white with a tinge of yellow : spire short ; apex 

 blunt and flattened: whorls 4-5, convex, the last occupies f of the 

 spire : suture slight, but wide in consequence of the upper part of 

 each whorl being compressed and shouldered : mouth oval : outer lip 

 thick-edged, somewhat expanding, extending beyond the upper 

 opening of the mouth, and angulated in that part, round below : 

 inner lip completely lining the base, and forming in the middle a 

 semicircular pad, which is separated and defined by a narrow furrow 

 or groove : umbilicus rather concave unless where it is closed near 

 the pillar by the pad. L. 0-3, B. 0-275. A fragment of one 

 specimen indicates a somewhat larger size. 



' Covered with a lid. 



