187 



Petitia Stokesiana, Chitty. 



Hab. ? Hanover (unique). 



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

 growth visible : 4 widely separated, rather strong, slightly raised, 

 rounded spiral carinse ; 1 finer ; 2nd to 7th strong, and 1 finer close 

 below ; 8th strong (the one at the periphery strongest and rather 

 sharp), and 2 very faint, round, and distant from the umbilicus ; on 

 the upper whorls 5. Spire, very little elevated, with rather concave 

 outlines. Apex, somewhat mammiform. Whorls, 4, well rounded, 

 with a deep suture. Aperture, semicircular, altogether rather de- 

 pressed, very slightly constricted, not spreading, moderately detached 

 from penult whorl. Labrum, scarcely produced above, thickened, 

 slightly reflected ; smooth and white, not pectinated. Labium, well 

 detached from body-whorl, on a plane with labrum, almost straight 

 within the aperture, white, thickened and expanded towards the um- 

 bilicus, much so below, but most so and somewhat pointedly in its 

 centre. Umbilicus, broad and deep. Labral lamella, much ex- 

 panded at a distance from its junction with the labrum, becoming 

 very fine as it fades into the umbilicus. Operculum, ? 



Height 0-04!), greatest breadth 0-08, least breadth 0-061. 



Named in compliment to Capt. Lort Stokes, R.N., late of H.M.S. 

 ' Acheron,' a zealous collector. 



Petitia Grevilleana, Chitty. 



Hab. Yallahs Hill. 



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

 growth visible ; 5 strong spiral carina?, with 5 less strong intervening : 

 on the upper whorls, 2 strong, with the lesser intermediate ones 

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

 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, stria 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 whorls 3. Spire, much depressed with convex outlines. 



