128 J. Starkie Gardner — On the Gault Aporrhaidm. 



and the outer lip sinuous : the anterior canal very long, slender 

 and tapering ; the columellar lip is incrusted. The length of the 

 spire is -023, and the canal '017 ; the breadth, including wing, -024. 



Distribution. — It is rare at Folkestone, and is not recorded else- 

 where in England. It is found in France and Switzerland — in the 

 Paris basin, atErvy, Dienville (specimens in the Sorbonne Museum), 

 Girandot, Ste. -Croix, etc. 



History. — This species was described by Sowerby in 1832 as 

 a Fusus, and named by him carinella, in the Trans. Geol. Soc. 2nd 

 series, vol. iii. p. 418, pi. 39, f. 24, and qiioted by Michelin, Mem. 

 Soc. Geol. vol. iii. p. 100, 1838, without description, as a Bostellaria. 

 In 1842 D'Orbigny, in the Pal. Franc. Terr. Cret., vol. ii. p. 287, pi. 

 207, figs. 7 and 8, gave an excellent figure of this form. It seems 

 to have had a wide range, being mentioned in the Prodrome, and by 

 Cornuel in 1851 from the Haute-Marne, by Cotteau, 1854, and 

 Eaulin and Leymerie, 1858, from the Yonne. In 1864 it was 

 figured by Pictet and Campiche, pi. 94, figs. 4 — 7, p. 616 ; the only 

 difference between their figures and the present arises from the im- 

 perfection of the specimens they had to describe, as the striae and 

 tuberculated carina are only seen on very well perserved examples. 

 In 1865, Mr. E. Tate mentioned it as a British species, and in 1869 

 it is found in Jaccard's list from the Middle Gault of Ste.-Croix. 



Aporrhais calcarata, J. Sowerby. Plate V. Figs. 7-14a. 



Description. — Shell moderately elongated, conical; spire forming 

 an angle averaging about 32°, diminishing rapidly towards the apex, 

 which forms an obtuse termination ; it is composed of six convex 

 whorls. The whorls are finely but very distinctly striated spirally, 

 ornamented transversely by many oblique, flexuous and equal ribs. 

 Commencing from the apex, the first three whorls have a prominent 

 angular, median keel, the transverse ribs not becoming visible till the 

 third whorl ; on the fourth and fifth the keel is hidden by the succeeding 

 whorls, to reappear on the last. On these (the fourth and fifth whorls) 

 the ribs are also very pronounced, and are still quite visible on the 

 posterior region of the last. The last whorl has therefore a salient, 

 angular keel at about its centre, and a less salient keel anterior to it ; the 

 region posterior to the dominant keel is ornamented by transverse 

 ribs, similar to those on the other whorls, and, as stated above, the 

 keel is continued up the spire, but is hidden by the suture ; the 

 remainder of the whorl is finely but distinctly and regularly striated. 

 The dominant keel is prolonged in a strong, striated, and acute 

 narrow and simple digitation, at first at right angles to the axis, 

 and then curving gradually upwards, it exceeds the spire in length, 

 and terminates in a sharp point. In many sjaecimens, however, it is 

 shorter, and perhaps a little broader. The aperture is narrow, and 

 is encrusted on the columellar side ; the anterior canal is long and 

 straight ; the outer lip is toothed ; and the. wing applied to the last 

 whorl only. The average length of the shell is about "006 ; they are 

 found at Blackdown as long as -020. 



In a specimen from an upper bed of the Gault at Folkestone, Fig. 

 10, there are more whorls, the keels near the apex are less visible, 



