BIVALVIA. 125 
Charlesworth has shown me a specimen of swborbicularis from the Red Crag in a crypt 
with a Pholas. 
The new species of Kellia described by Forbes in his ‘Aigean Report, 1843, 
cannot now be found, and his short descriptions, unaccompanied by figures, are insufficient 
for specific determination. Perhaps his Kel/ia transversa may be the same as my 
Scacchia cycladia, but 1 cannot alter the name of my shell upon such uncertainty. 
Scintinta ampiaua, Wyst. Crag Moll., vol. ui, p. 120, Tab. XII, fig. 11 (as Kelha 
ambigua). 
ScINTILLA AMBIGUA? Desh. An. sans. Vert., t. i, p. 700, pl. xlix, figs. 13—15. 
Localities. Cor. Crag, Sutton, and near Orford. Red Crag, Walton and Sutton. 
Chillesford Bed, Chillesford and Aldeby. 
In Mr. Jeffreys’ list of Cor. Crag shells (‘ Quart. Journ. Geo. Soc.,’ vol. xxvii, p. 139) 
this species is referred to Hrycina pusilla, Phil., but in the same Journal subsequently, at 
p- 493, Mr. Jeffreys says that “Kellia ambigua is not Hrycina pusilla, Phil., but Seimtilla 
Parisiensis of Conti.” THe has since written to me that he now refers it to Kellia 
Geoffroyi, Payr, of which he sent me a specimen for comparison. I find that shell, 
however, to be covered with fine radiating lines, of which I can detect no trace in the 
numerous specimens of ambigua in good preservation which I have examined. I have 
therefore retained the name ambigua, Nyst, under which 1 originally described this shell, 
merely changing the generic appellation. 
The name of Scacchia elliptica is given in the same list by Mr. Jeffreys, at p. 485, as 
a species new to the Red Crag. On application to Dr. Reed, of York, in whose cabinet 
is the specimen on which this introduction of the species as a Red Crag shell is founded, 
he obligingly sent it to me for examination, and I find it to belong to Scentilla ambigua, 
which I had given as a Red Crag species in ‘Crag Moll., vol. 1, p. 121. Seacchia 
elliptica is abundant in the Cor. Crag at Sutton, as is also Scentilla ambigua, but the latter 
becomes very rare in the newer Formations (where it appears to have died out), and is, 
moreover, exceedingly variable in its outline as well as in the degree of its tumidity. 
Monracura srpentaTa, Wont. Crag Moll., vol. u, p. 126, Tab. XII, fig. 17. 
Localities. Cor. Crag, Sutton, and near Orford. Red Crag, Walton Naze. Chiulles- 
ford Bed, Aldeby. Middle Glacial, Hopton. Post Glacial, Nar Brickearth, at Pentney. 
This species has been obtained by Messrs. Crowfoot and Dowson from Aldeby, by 
my son (a single valve) from Hopton, and by Mr. Rose from Pentney. The specimen 
upon which the species was given as from Bridlington in ‘Mem. Geol. Survey,’ vol. i, p. 
409, 1846, was in the Bowerbank collection now in the British Museum, and had, 
