GASTEROPODA. 19 



association with crispata. I am disposed to think that incrassata is entitled to specific 

 value ; it much resembles Fasus decemcostatus, Gould. The common living British form, 

 crispata, occurs in the fen gravels, and is said to be abundant at Kelsea Hill. 

 P. incrassata is given in Woodward'.s list as from Thorpe, but rare. 



Trophon 1 antiquus, var. striatus. Crag. Moll., vol. i, p. 44, Tab. V, fig. 1, c, d. 



Localities. Red Crag passim, except Walton and Bentley. Fluvio-marine Crag 

 passim; Chil. bed, Horstead, Coltishall, Aldeby, and Easton Bavent. Lower Glacial, 

 Belaugh, Rackheath, and Weybourne. Middle Glacial, Hopton and Billockby. 



Trophon antiquus, var. striatus contrarius. Id. Tab., fig. 1, d, e,f,g, i,j. 



Localities. Red Crag passim. Fluvio-marine Crag passim ; Chillesford bed, 

 Horstead, Coltishall, Aldeby, and Easton Bavent. Lower Glacial, Belaugh, Rackheath, 

 and Weybourne. Middle Glacial, Billockby ? 



Trophon antiquus, var. carinatus. Id. Tab., fig. 1, a, b. 



Localities. Red Crag, Sutton and Butley. Fluvio-marine Crag, Bramerton ? 

 Upper Glacial, Bridlington {Woodward). 



Trophon antiquus, var. carinatus contrarius. Id. Tab., fig. 1, k. Supplement, 



Tab. I, fig. 10, a, b, c. 



Localities. Red Crag, Newbourn. Fluvio-marine Crag, Bramerton ? Upper 

 Glacial, Bridlington. 



Some few years since, I found at Newbourn a specimen of this sinistral shell, which 

 exhibits three ridges of carinas upon the upper volution, and these are continued over the 

 body-whorl, a form of sculpture I had not before seen upon any Crag specimens from 

 Suffolk or Essex, and I have also had figured, by the obliging permission of the Com- 

 mittee of the Norwich Museum, a specimen of this reversed form which has the same 

 carinas, even more prominent (fig. 10, a) ; this latter shell was presented to the Museum 



1 Neptunea, Bolten, 1798, has been proposed by Messrs. H. and A. Adams as a generic name for this 

 shell. Tritonium, 0. Fabr., was adopted by Loven, and this has precedence ; but it is difficult now to say 

 what species was intended as the type of that genus. The name of Trophon* has been previously given 

 to my Crag shells, and as the differences between these are merely artificial or conventional, I have here 

 retained the one I employed in the ' Crag Mollusca.' 



* Trophon appears to be masculine, being, according to Mr. Jeffreys, a contraction of Trophonius. 



