GASTEROPODA. 7] 
Hyprosia viva, Pennant. Supplement, Tab. IV, fig. 23. Crag Moll., vol. i, p. 109 
(as Paludestrina ulv@). 
TurBo utvm, Penn. Brit. Zool., 4th ed., vol. iv, p. 132, pl. Ixxxvi, fig. 120. 
Localtties. Red Crag, Walton (Bell)? Fluvio-marine Crag, Yarn Hill, near 
Southwold. Chillesford bed, Aldeby. Post-glacial, Gedgrave. 
This species I have not seen as fossil from either of those purely marine formations, 
the Coralline and Red Crags. The specimen figured is from a formation at Gedgrave, 
mentioned in vol. i, p. 109, which is, I believe, a post-glacial bed, where land and 
freshwater shells of an old post-glacial period are intermixed with a re-deposit of Coralline 
Crag derivatives. It has been found by Mr. Reeve in the Fluvio-marine Crag at 
Bramerton, and by Messrs. Dowson and Crowfoot at Yarn Hill and Aldeby. This 
species is given by Mr. Bell from Walton (‘ Ann. and Mag. Nat. Hist.,’ Sept., 1870), 
but I have not seen the shell. 
Hypropia supumBinicata, Mont. Crag Moll., vol. i, p. 108, Tab. XI, fig. 2 (as 
Paludestrina subumbilicata). 
Locahties. Fluvio-marine Crag, Bramerton. Chillesford bed, Bramerton. 
This species, so very common in the Fluvio-marine Crag at Bramerton, is, I am 
informed, very rare in the Marine Chillesford bed at that place, and I have not met 
with it in the Chillesford bed elsewhere, nor in the Lower or Middle Glacial Sands. J 
agree in the distinction drawn by Montagu between this shell aud its congeners w/v@ and 
ventrosa ; and distinct from all these is, in my opinion, Hydrobia thermalis (Helix 
octona?, Linn.), Crag Moll., vol. ii, p. 319, Tab. XXXJ, fig. 12, to which I have referred 
the shells found in the freshwater (older post-glacial) deposits of Clacton and Grays. 
Rissoa proxima, Alder. Supplement, Tab. IV, fig. 17. 
Rrssoa Proxima, Alder MS. Thompson, An. Nat. Hist., vol. xx, p. 174. 
Locality. Corallie Crag, Sutton. 
In deference to the British conchologists, I have separated two specimens which I had 
considered as varieties of #. vitrea. They were pointed out to me by Mr. Jeffreys as 
specifically distinct. he striae with which they are covered (which are not very visible 
in my fossils) appear to be the only character by which they can be distinguished. 
