The Hon. E. Chitty on Me Stoastomidse. 147 



Petitia Adamsiana, Cliitty. 



Ilah. New Hope, Old Hope, and a smaller variety on the road 

 east of the *' Water-wheel," Westmoreland. 



i'^orwz, glohose-discoidal. Co^wr, reddish horn. Sculpture, \^ verj 

 strong spiral carinse, with between the 1st and 2nd and 2nd and 3rd, 

 1 each rather less strong ; between the 3rd and 4th and 4th and 

 5th, 3 each less strong ; between the 5th and 6th, 1 less strong ; 

 between the 6 th and 7th, 3 less strong ; between the 7th and 8th, 

 1 less strong, and none between the remaining strong carinse. Lines 

 of growth very faint ; on the upper whorls, 4 strong carinae with in- 

 tervening less strong. Spire, slightly elevated, with rather convex 

 outlines. Whorls, A^, very slightly rounded and with a very slight 

 suture ; last whorl slightly swelling behind the labrum, and slightly 

 constricted at the aperture. Aperture, very slightly expanded and 

 scarcely detached from the penult whorl. Labrum, appressed to the 

 body -whorl, not produced much thickened, slightly double below ; 

 smooth and simple. Labium, much thickened and reflected towards 

 the umbilicus in its centre, slightly curved to the right below ; well 

 detached from the body-whorl. Umbilicus, moderately deep, co- 

 vered by an expansion very convex externally of the labral lamella, 

 which is much produced immediately after leaving the labrum, and 

 then becomes abruptly narrowed till it joins the body-whorl. In the 

 labral lamella it approaches the subgenus Agassizia. Operculum, 

 very peculiar, deeply concave in the centre and studded with very fine 

 granulations ; edge all round very much thickened and folded over 

 in vertical plaits outside, especially at the lower end of the labial 

 side ; throughout the labial side overlapping the labium with sharp, 

 fine, numerous raised lamellae on the labral side. 



Height 0-062, greatest breadth 0-09, least breadth 0-077. 



Var. a. 



From near " Water Wheel." 



Height 0-044, greatest breadth 0*076, least breadth 0*061. 

 Named in honour to the memory of the late Professor C. B. 

 Adams of America, my friend and conchological master. 



Petitia Tayloriana, Chitty. 



Hab. ? St. Ann's. 



Form, globose-discoid. Colour, pale horn. Sculpture, 24 fine, 

 sharp, inequidistant, spiral carinse, 6 of which interspersed are rather 

 strong ; on the upper whorls 5 . Spire, very slightly elevated, with 

 convex outlines. Whorls, 4, slightly rounded, with a slight suture. 

 Aperture, very slightly constricted behind the labrum, and slightly 

 expanding ; scarcely detached from the body- whorl ; slightly de- 

 pressed above and expanded below. Labrum, white, shortly reflected, 

 not produced above, very little pectinated by the stronger spiral 

 carinse ; slightly double below. Labium, on a plane with labrum, 

 straight, appressed above to the body-whorl. Umbilicus, rather 

 deep and narrow. Lahral lamella, scarcely produced. Operculum^ 



10* 



