HIMA. 49 



N. NUCLEOLUS, Phil. PI. 15, fig. 262, 



Whitish, brown at suture and base, with usually a brown 

 central band. Length. 5-fi-5 mill. 



Mazatlan ; Acapulco W. M. Gabb. 



This is one of the few Mazatlaii species unknown to Carpen- 

 ter ; it is a very distinct and pretty form. 



X. INCRASSATA, Strom. PI. 15, figs. 263-266. 



Brownish white, usually obscurely maculate or banded with 

 brown ; whorls with or without a slight shoulder ; shell broad 

 to elongated ovate; occasionally (in some specimens) with a 

 varix crossing the whorl; lip varix strong, usually with three 

 rown spots. Length, -45--(> inch. 



Iceland, and North Europe to Azores, Mediterranean. 

 Fossil, widely distributed in European tertiary and quaternary 

 posits. Owing to the great variability of this species, it has 

 eived numerous names: one of these forms, indeed, is usually 

 para ted by some of the best European conchologists, and it 

 ill be as well, perhaps, to designate it as var. pygmaea, although 

 the immense series of specimens before me compels me to agree 

 with Dr. von Martens, that it has no real claim to specific dis- 

 tinctness. 



Var. PYGMJEA, Lam. Fig. 265. 



Shell narrower and more finely sculptured ; whorls rounded, 

 not augulated above ; spire proportionately longer. 



A", iiwrassata is a very active mollusk. and now and then 

 changes its crawling position by leisurely floating with its foot 

 upwards. It often gets into lobster and whelk pots. The spawn 

 cases are solitary, yellowish, and shaped like a round flask, witli 

 a. small neck or opening at the top. 



X. ROSACKA, Keeve. PI. 15, fig. 267. 



Deep rose-color, black edged at the base, lip white. 



Length, S-5 mill. 



Habitat unknown. 

 May be a variety of N. incra^ntn. 



X. PROMPT A. Marrat. 



Ovately conical, highly polished, pale yellowish white, with 

 two reddish-purple dotted bands, one in the centre of the body- 



