GASTHROPODA. 19 
association with crispata. I am disposed to think that zuerassata is entitled to specific 
value; it much resembles Fusus 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’ ANTIQUUS, var. sTRIATUS. Crag. Moll., vol. i, p. 44, Tab. V, fig. 1, ¢, 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, 9, 2,7. 
Localities. Red Crag passim. Fluvio-marine Crag passim; Chillesford bed, 
Horstead, Coltishall, Aldeby, and Kaston Bavent. Lower Glacial, Belaugh, Rackheath, 
and Weybourne. Middle Glacial, Billockby ? 
TROPHON ANTIQUUS, var. cARINATUS. Id. Tab., fig. 1, a, 0. 
Localities. Red Crag, Sutton and Butley. Fluvio-marime Crag, Bramerton? 
Upper Glacial, Bridlington (Woodward). 
TROPHON ANTIQUUS, var. CARINATUS conTRARIUS. Id. Tab., fig. 1, 4. Supplement, 
Malo. Il, te LO, G @ @ 
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 carinze 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 trom 
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 
carine, even more prominent (fig. 10, a) ; this latter shell was presented to the Museum 
' Neptunea, Bolten, 1798, has been proposed by Messrs. H. and A. Adams as a generic name for this 
shell. Tritonium, O. 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. 
