The Hon. E. Chitty on the StOcastomida?. 149 



Petitia Grevilleana, Chitty. 



JIah, Yallahs Hill. 



Form, globose-discoid. Colour, pale horn. Sculpture, striae of 

 growth visible ; 5 strong spiral carina3, with 5 less strong intervening : 

 on the upper w^horls, 2 strong, with the lesser intermediate ones 

 (this might almost be classed in the 2nd division of TVilkinsoncea). 

 Spire, slightly elevated, with straight outlines. Whorls, 3|rds, well 

 rounded, with a well impressed suture. Aperture, obliquely elliptic, 

 more expanded in the upper than lower portion, slightly campanulate 

 on the right owing to a slight constriction behind the labrum. La- 

 brum, very slightly produced above, thickened and reflected at about 

 its middle. Labium, below the plane of the labrum above, slightly 

 curved to the right below and thickened, slightly detached from 

 body -whorl. Umbilicus, not deep, broad. Labral lamella, slightly 

 developed. Operculum, moderately concave, shining, but with very 

 fine granulations. 



Height 0-05, greatest breadth 0-069, least breadth 0*057. 



Named in compliment to my friend Dr. R. K. Greville, of Edin- 

 burgh. 



Petitia Carpenteriana, Chitty. 



Hab, Pool's Rock, Hanover. 



Form, globose-discoid. Colour, ? Sculpture, striae of growth 



visible : 8 strongest spiral carinse and 1 strong ; 5 strongest and 1 

 strong in each interspace ; and 2 stronger round the umbilicus : on 

 the upper w^horls 3. Spire, much depressed with convex outlines. 

 Wholes, 3f rds, moderately rounded, with a deep suture. Aperture, 

 semicircular, rather constricted behind the labrum, not expanded, 

 very slightl}^ detached from the body- whorl. Labrum, not produced 

 above, smooth, rather double, inner edge sharp, the strongest lines 

 terminating abruptly at the outer edge. Labium, very slightly 

 curved to the right below, well detached from the body-whorl, lower 

 than the plane of the labrum below. Umbilicus, very shallow and 

 broad, much covered by the labral lamella, which is much and widely 

 produced above. Operculum, ? 



Height 0-038, greatest breadth 0*07, least breadth 0'0o4. 



Named in compliment to P. P. Carpenter, Esq., of Warrington, 

 author of an excellent Catalogue of the Mazatlan Shells in the British 

 Museum. 



Petitia (? Lewisia) Barroniana, Chitty. 



Hab. ? (unique). 



Form, globose-discoidal. Colour, ? Sculpture, 20 spiral 



carinse, 7 of which are rather more prominent, namely the 2nd, 4th, 

 8th, 12th, 16th, 18th and 19th: on the upper whorls, 6. Striae of 

 growth visible. Spire, much depressed, with straight outlines. 

 Whorls, 4, moderately rounded, with a light suture. Aperture, much 

 constricted at the labrum, semicircular, widely separated from the 

 body-whorl. Labrum, not produced above, simple, thin, rather 



