166 SUPPLEMENT TO THE CRAG MOLLUSCA. 
PHOLADIDEA PAPyRACcEA, Solander. Supplement, Tab. X, fig. 27, and Crag Moll., vol. ii, 
p- 298, Tab. XXX, fig. 10. 
Locality. Cor. Crag, Sutton. 
In the ‘ Crag Moll.’ I figured two disconnected fragments from the Cor. Crag of Sutton 
of what appeared to me to belong to this species, and I have recently found a small 
specimen which undoubtedly belongs to it. This is figured in Tab. X of this 
Supplement and is from the same locality of Sutton. 
In Mr. Jeffreys’ list appended to Mr. Prestwich’s paper (p. 485) this species is given 
as occurring in the Red Crag, but as no special locality is mentioned for it and I have 
not been able to see the specimen, I cannot admit the species as a Red Crag one. 
The figure I gave in ‘ Crag Moll.,’ Pl. XXXI, fig. 23, is the representation of what 
I believe to be an extraneous fossil doubtfully belonging to this genus. 
BRACHIOPODA.’ 
This division of the Mollusca is composed of animals that are considered to be of 
lower organisation than the Bivalvia. Although Brachiopoda are strictly bivalvia they 
differ essentially in their internal organisation from the rest of that class, and they have 
im consequence been separated from that section of the Mollusca. 
The animals and shells of this group have been thoroughly examined by several of 
our ablest comparative anatomists and microscopists, and I must refer the reader to 
the elaborate work of Mr. Davidson, where the history of the entire Order is most ably 
given. 
Although I defer to the much better knowledge of the subject, and adopt the terms 
of that gentleman, I cannot but repeat the objection which in my ‘ Monograph of the 
Bivalves of the Eocene Mollusca’ I have made to the terms “anterior” and “ posterior ” 
1 The name of the ‘Crag Mollusca’ given to my Monograph has been objected to, on account of its 
omitting a portion of the fossils belonging to this class, and, therefore, does not fulfil the conditions 
required by the title. It was originally intended that the work should comprise everything belonging to 
the Mollusca which has been found in the Crag, but after its commencement Mr. Davidson undertook to 
describe for the Paleeontographical Society all the fossil Brachiopoda of Great Britain, and I thought those 
of the Crag ceuld not be excluded. The Crag Brachiopoda being so few, and a desire having been expressed 
by several persons that the ‘ Mollusca of the Crag’ should be made complete, the opportunity afforded by 
the Supplement has been taken to include them. 
