120 NACELLA. 



Reeve's P. chiloensis (pi. 45, figs. 20, 21,) is similar to atramentosa 

 but darker. 



The P. venosa Rve. (pi. 45, figs. 24-27) is rounded, the ribs almost 

 completely obsolete, painted with divaricating stripes. The interior 

 is peculiarly rich in coloring, being suffused with bronze-red, the 

 muscle-scar lilac. Numbers of this form are before me. 



I suppose the P. areolata Gmel. (Syst., p. 3716 ; Wood's Index, pi. 

 38, f. 70) to be the same as venosa. 



N. iNRADiATA Reeve. PL 20, figs. 43, 44. 



Shell ovate, elevately convex, somewhat compressed at the sides, 

 everywhere rather obsoletely, radiately latticed ; whitish, obscurely 

 rayed with a very few red lines in pairs, lines irregular, distorted. 

 Interior white, red lines distinct, chestnut in the middle. (Rve.) 



Habitat unknown. 



P. inradiata Reeve, Conch. Icon., f. 77. Jan., 1855. 



A deep cup-like opaque-white shell, obscurely latticed throughout, 

 irregularly rayed with a few straggling red lines, which are most dis- 

 tinctly seen in the interior. (Rue.) 



This is a form I have not seen. It may prove to be one of the 

 many color-varieties of P. ce^iea var. deaurata. 



N. POLARIS Hombron & Jacquinot. PI. 49, figs. 21-27. 



Shell oblong-ovate, more or less compressed, sculptured with 

 rounded, rather distant, sparingly nodose radiating ribs, often 

 obsolete ; margin roundly crenated ; exterior usually eroded 

 brown ; interior shining bronze-black ; vertex inclined forward, 

 situated at the front s-f of the length. (31.) 

 Length 51, breadth 36, alt. 23 mill. 

 Length 48, breadth 35, alt. 26 mill, (especially high.) 

 Length 59, breadth 40, alt. 22 mill (the longest, rather flat.) 

 Length 47, breadth 33, alt. 14 mill, (the flattest.) 



South Georgia. 



P. polaris Martens & Pfeffer, Mollusken von Siid Georgien, 

 in Jahrb. der Hamburgischen Wissenschaftlichen Anstalten iii, p. 

 101, t. 2, f. 11-13 (18&6).— P. polaris H. & J., Ann. des Sci. Nat. 

 (ii) xvi, p. 191, (1841.) 



P. kerguelensis E. A. Smith is notably -wider posteriorly, and is 

 not so dark inside. (Mart.) 



