GASTEROPODA. 39 



volution, between which and the suture is the sinuation curving backwards. Considering 

 it different, I have given to it the above specific name. 



Pleurotoma scalaris ? Moller. Supplement, Tab. Ill, fig. 12 



Defrancia scalaris, Moll. Ind. Moll. Groenl., p. 12, 18-12. 



Locality. Upper Glacial, Bridlington. 



This was also sent to me by Mr. Leckenby, aud with the specimen is a label on which 

 is written, " considered by J. G. J. to be a large example of Mang. pyramidalis" It 

 seems to correspond with the description given by Moller of his species scalaris, and I 

 have ventured, with a doubt, to refer it accordingly. 



Mangelia cinerea, Moller, is given in Woodward's List as a species from Bridlington, 

 which I have not been able to find. The nearest approach to cinerea is a shell represented 

 in 'Crag Moll.,' vol. i, p. 64, Tab. VII, fig. 15, as Clavatula plicifera. 



Defrancia cinerea, Moll., in British Museum is probably an elongated var. of scalaris. 

 These forms all depart from turricula in the absence of the prominent shoulder of that 

 species. 



Pleurotoma Dowsoni, S. Wood. Supplement, Tab. Ill, figs, 13 and 14. 



Spec. Char. PL Testa ovato-fasiformi, clathrata ; anfractihus convexis, tumidiuscidis, 

 juxta suturam angulatis, lo/igitudinaliter lineis ewinenlibas cinctis, transversim plicatis ; spira 

 breviore. 



Length, -j^ths. 



Localities. Chillesford bed, Alcleby. Middle Glacial, Billockby, and Hopton? 

 Upper Glacial, Bridlington. 



One specimen was sent to me as from Bridlington, fig. 14, by Mr. Leckenby, and 

 another, fig. 1 3, from Alcleby, was found by Messrs. Crowfoot and Dowson. They approach 

 the recent exarata of Moller, but are shorter and much more tumid. These two 

 specimens are in excellent preservation. About a dozen specimens of a shell from the 

 Middle Glacial of Hopton and Billockby appear to belong to this species, but they are too 

 much mutilated to enable me to refer them to it without a note of interrogation. They 

 agree in the tumid form, and in so much of the sculpture as is preserved, their ribs being 

 fewer than those of proximo,. I have named the shell after Mr. E. T. Dowson, of 

 Geldeston, to whose industry, in association with Mr. W. M. Crowfoot, of Beccles, we 

 are indebted for so complete a fauna of the Aldeby deposit. 



