4 THIRD SUPPLEMENT TO THE CRAG MOLLUSCA. 



pond with his variety C, given in fig. 11 of Tab. I of his work, while the present shell 

 corresponds with his fig. 16 of the same plate. [Our specimen therefore seems to have 

 got into the Red Crag from some bed corresponding to those of the Bolderberg. — Ed.] 



I found also among my siftings in the Red Crag at Eelixstowe a considerable portion 

 of a specimen of a species belonging to this genus with very distinct ornamental ridges 

 or costae which appears to correspond or at least to approach nearer to Pleurotoma 

 abnormis of F. Edwards, ' Eocene MoUusca,' p. 294, Tab. XXX, fig. 14, a. b.^ than to 

 any other species I have compared it with. This being a London Clay species it may 

 have come into the Red Crag with the Bostellaria which I have figured. I also obtained 

 a fragment of what seems to be Pleurotoma Gastaldi, Bellardi, Tab. II, fig. 19, but neither 

 of them being in a condition to allow of correct determination I have not thought it 

 worth while to have them figured. 



Fig. 5 of Tab. I, represents one of two small specimens kindly sent to me by Dr. 

 Reed with the name of Pleurotoma gracilior, A. Bell, from the Red Crag of AYalton 

 Naze affixed to it. These appear to have lost their outer coating, but are the same as 

 the shell represented in fig. 12 of Tab. VII of vol. i of ' Crag. Moll.,' under the name 

 lavigata, Phil., and which at p. 41 of my first Supp., is referred to P. tenuistriata, 

 A. Bell. One of them has the upper whorls destroyed, but the other has all the whorls 

 perfect and so peculiar that I have had it represented. It shows not only an obtuse 

 apical region, but the first volutions are wholly different from the more cyhndrical 

 volutions of the rest of the shell. 



Pleurotoma nebula, Mont. 3rd Supp., Tab. I, fig. 7. 



Fusus ? NEBULA, 5. Wood Catal. Mag. Nat. Hist., p. 541, 1842. 

 Clavatula — — Crag Moll., vol. i, p. 60, tab. vii, fig. 10, i848. 



Pleueotoma — — 1st Supplement, p. 45, tab. vii, fig. 7, 18/2. 



Mangelia — Ford. Sf Hani Brit. Moll., vol. iii, p. 4/6, pi. 114, figs. 7— 9, 1853. 



Although I have already given two figures of the Crag shell under the above specific 

 name, they neither of them show a satisfactory representation of this long known species, 

 and I have therefore determined to give another of a specimen in a more perfect condition 

 from the cabinet of Mr. Robert Bell, which has retained some of its spiral striae. 



