7s 147 
November 8, 1842. 
R. C. Griffith, Esq., in the Chair. 
An extract of a letter from the Society’s President, the Earl of 
Derby, was read. His Lordship observes, with reference to some 
young Rheas hatched in the menagerie, that the eggs were laid in 
one of his Lordship’s paddocks, and were collected into a nest by the 
male bird, who sat upon them very perseveringly until the keeper, 
thinking the spot selected was too exposed, removed the eggs and 
placed them under some Turkeys. They were ultimately, however, 
placed in Mr. Appleyard’s hatching apparatus, and in about a week 
or ten days were hatched. ‘The letter moreover announces the safe 
arrival of three Elands (Antilope Oreas, Pall.) in his Lordship’s me- 
nagerie. 
A memoir on the anatomy of a species of Calyptrea with a ven- 
tral shelly valve (Lithedaphus longirostris, Ow.), by Prof. Owen, was 
then read. The normal valve secreted by the Lithedaphus resembles 
‘a Calyptrea, and indeed is possibly a variety of the Calyptrea 
equestris of authors; but the animal is inclosed, like the Acepha- 
lous Mollusks, in a bivalve shell. The additional plate, in the 
present instance, Professor Owen shows to be connected with a mo- 
dification in the organization of the animal which establishes its 
claim to a subgeneric distinction among the Calypireide. The 
specimens dissected were collected by H. Cuming, Esq. in the Phi- 
lippine Islands, and the circumstances connected with this discovery 
are recorded by that gentleman in the ‘ Conchologia Systematica’ of 
Mr. L. Reeve (vol. 11. p. 31). 
“ Lithedaphus differs from all previously described Calyptr aide i in 
some well-marked external characters of its soft parts. The head, 
instead of being short, broad and flat, is long and subcylindrical ; 
the part anterior to the tentacles being produced in the form of a 
proboscis, equalling in length the whole ‘body behind it, and termi- 
nated by a clavate extremity. The tentacles or antenne are of pro- 
portional length, reaching, in some specimens, to the beginning of 
the terminal expansion of the proboscis. The second external cha- 
racter is a moderately long subcompressed process, projecting for- 
wards between the head and the anterior margin of the foot, like a 
second head, but consisting only of a soft duplicature of the mantle, 
with muscular fibres for protraction and retraction. In some speci- 
mens the apex of this process was expanded and a little produced on 
each side. : 
“The foot, in the specimens examined, was much smaller in pro- 
portion than in Calyptrea or Calypeopsis; it presents a subcircular 
form, as in Cal. Sinensis, but only equals half the diameter of the 
No. CXVIII.—Procrrpines or THE Zoox. Soc. 
