118 



PUOCEKDINGS OF THE MALACOLOGICAL SOCIETY. 



depression without forming any inner area (or nmbilical zone). Body- 

 chamber occupying half a whorl; aperture oblique, oval, expanded 

 near the periphery, somewhat contracted at the umbilicus, peristome 

 slightly thickened and everted, especially near the umbilicus, hypo- 

 nomic sinus wide and deep. Chambers rather deep, about sixteen 

 or seventeen in a whorl ; septa moderately convex, suture-line with 

 a broad, shallow, lateral sinus, and nearly straight on the periphery. 



Fig. I. — Nmttihts Dradfordensls, n.sp. «, lateral view of an example of the less 

 inflated form ; b, front view of the same. Inferior Oolite {coiwarus-zone) : 

 Bradford Abbas, Dorset. Drawn from a specimen in the British Museum 

 Collection [C. 4503]. About five-sixths natural size. 



Siphuncle extra-medial. Test almost smooth, ornamented only with 

 growth-lines, which form on the periphery a deep wide sinus corre- 

 sponding to the hyponomic sinus of the aperture. 



Dimensions. 



Diameter 



(i) 



70 mm. 



(ii) 



64 mm. 



(iii) 

 42 mm. 



Height of outer whorl ... 



43 „ 



39 „ 



26 „ 



Height of outer whorl above ) 

 preceding whorl ) 

 Thickness 



31 „ 

 43 „ 



26-5 „ 

 41 „ 



27 mm 



Remarhs. — This species is represented in the British Museum by the 

 three examples the dimensions of which are given above, viz., Nos. 

 C. 4503 (i), C. 3177 (ii), and C. 4256 (iii). In one of these specimens 

 (No. C. 3177) the anterior border of the annulus and of one of the 

 shell- muscles is shown on the internal cast of the body- chamber as 

 a sharply incised line which crosses the periphery in a shallow sinus 

 13 mm. in advance of the last septum, and on reaching the lateral area 

 turns forward and crosses that area in a bold strongly convex curve. 



