74 FAUNA OF THE CORNBRASH. 



Aptyxiella lineata, sp. nov. Plate VII, fig. 18. 



Type. — A fragment of length 29 mm. Maximum breadth 8 mm. Spiral angle 

 6°. Three whorls are shown. The suture makes an angle of 74° with the axis. 

 The surface of the shell is nearly conical, the sutures being very little impressed. 

 The ornament consists of fine spiral lines ; the base is angular and smooth ; the 

 aperture channeled in front. No folds are seen at either end. From the neighbour- 

 hood of Chippenham. In the British Museum (no. 27422). 



Description. — The whorls seem to have a very thin shell, and sometimes show 

 nothing within, though sometimes with a quadrate interior and a spiral depression 

 along the middle of the outside of the whorl. 



Distribution. — There are two specimens from Chippenham, four have been 

 obtained at Shipton-on-Cherwell, and one at Holwell. They are usually in short 

 fragments, and appear to have been buried as such in a different matrix from that 

 which fills the interior. The general shape of the species shows a great resemblance 

 to that of N. sharmani from Boulogne, but that is said to have numerous folds. 



Aptyxiella blainvillei (Desl.). Plate VII, fig. 19. 



1843. Cerithium blainvillii, Deslongchamps, Mem. Soc. Linn. Nornmndie, p. 192, pi. viii, fig. 35. 



Type. — Shell turreted, very long in proportion to its diameter, striated trans- 

 versely ; whorls a little less high than broad, concave in the middle, slightly swollen 

 near the sutures, where they form a well-pronounced projecting angle; base slightly 

 concave ; aperture rhomboidal ; columella ending below by a canal in the form of a 

 straight, rather elongated beak. From the Pierre Blanche of Langrune. 



Description. — The figured specimen (PI. VII, fig. 19), so far as preserved, agrees 

 accurately with the above description, with the figure of the type, and with its 

 numerical data. It has no folds when cut. The number of spirals on each whorl 

 is normally four, but intervening feebler ones are seen on the final whorls. The 

 spiral angle is 16°, and the sutures make an angle of 77° with the axis. 



Distribution and Relations. — Five specimens of this shell have been collected at 

 Shipton-on-Cherwell for Mr. Hudleston, but none are known elsewhere. The 

 broader form known as G. defrancii has been united to this by some, but the latter 

 species differs from ours, certainly in its spiral angle, and possibly in the form of 

 its aperture. It comes also from a somewhat different facies of rock which may 

 be also lower. On the other hand, it is quite possible that our specimens come from 

 the beds underlying the Cornbrash, and not from the Cornbrash itself. The matrix 

 is only seen in the interior. 



