GASTEROPODA. 59 



This species is not rare in the Red Crag, but the specimens are generally more 

 or less rubbed. In those which are best preserved, fine impressed striae may be 

 detected between the ribs. It differs from CI. mitrula in having fewer costae, and a 

 more elevated spire ; and the ribs in this are more oblique, sloping to the left, and 

 preserving generally a continuous oblique line of ridge, interrupted only by the 

 suture ; the spaces between them are rather wider than the ribs, and the first two 

 volutions are destitute of costae, but are cancellated ; the aperture varies from one 

 third to two fifths of the length of the axis. The figure does not well represent 

 the ribs, as they slope a little more towards the upper part, and incline backwards. 

 The outer lip is sharp, with a thickened obtuse varix on the exterior, and it has 

 also a thickening upon the inside, particularly near the sinus, which is rather broad. 

 The figure by Nyst probably represents the same species, though my specimens are 

 all more slender and attenuated than his figure. It is, however, a doubtful iden- 

 tification, and he has described that shell as smooth ; my Crag specimens, when 

 perfect, are transversely striated. 



6. Clavatula mitrula. J. Soto. Tab. VII, fig. 7, 8 a. 



Buccinum mitrula. J. Sow. Min. Conch, t. 375, fig. 3, 1822. 

 Pleurotoma mitrula. S. Wood. Catalogue 1842. 



CI. Testa turritd, elongatd, subfusiformi, apice acuto ; anfractibus septem convexius- 

 culis, plicatis, plicis circa decern obliquis, sub lente tenuissime striatis ; striis transversis 

 impressis ; aperturd lanceolato-ovatd. 



Shell elongato-turriculate, subfusiform, costated ; whorls 7, slightly convex, 

 ornamented with about ten oblique, obtuse, rounded ribs, and finely striated trans- 

 versely, with a sharp and curved outer lip ; sinus a little below the suture. 



Axis, f of an inch. 



Locality. Cor. Crag, Sutton. 



Red Crag, Sutton and Walton Naze. 



This is an abundant species in the Red Crag. Good specimens are covered with 

 transverse impressed striaa. The ribs are very slightly curved, and are rather more 

 prominent on the upper part ; they are as wide as the spaces between them, and 

 rarely in a continuous line ; the apex is sharp, and the first two volutions are with- 

 out the large obtuse ribs, but are cancellated. The outer lip is slightly curved and 

 sharp ; it is marginated on the outside, and thickened within, particularly below 

 the sinus, and has a deep, distinct suture. The lower part of the outer lip projects 

 slightly, with a wide and rather short canal. Aperture about two fifths the length 

 of axis. It resembles in form PL multilineolatum, Phil. (t. 26, f. 1), but the whorls 

 are more convex. 



