129 
Professor HumpHRy complimented Mr Salter upon his 
clear and able exposition of the relation of the bivalves and 
univalves, as exemplifying the great principles of modification 
which may be observed in nature, shewing how with immense 
variety in detail there is little in principle. With regard to 
the water vascular system, he thought there was no reason why 
the organs should not be respiratory as well as excretory ; these 
functions being not unfrequently blended in the lower animals. 
Mr SEELEY did not admit Prof. M‘Coy’s claim to the re- 
lation of the muscles and valves; denied that the palpze in the 
Lamellibranchs corresponded in function with the spiral coils 
of the Brachiopods. These and the external covering of the 
brachiopod correspond much more nearly with those of the 
polyzoa; reference, he held, should rather be made to the 
radiata than the lamellibranchs. As a case in point, he in- 
stanced perforations common in the brachiopod shells. He 
thought the brachiopod diverged almost as far from the ordi- 
nary molluscan type, as do the echinodermata from the orders 
to which they are most nearly related. 
Mr SALTER in combating Mr Seeley’s remarks, said he 
preferred to seek analogies in those orders which had most 
resemblance rather than in those which had no external re- 
semblance. 
February 22, 1869. 
The PRESIDENT (PROFEssoR SeLwyn, D.D.), in the Chair, 
Communications to the Society ; 
(1) On the bird-like characters of the Brain and Meta- 
tarsus in the Pterodactylus from the Cambridge 
Greensand. By Mr H. Sretny, F.G.S. 
This was a note upon a specimen of the skull of Pterodac- 
tylus, which had been obtained by Mr Walker (Sidney Sussex 
College), and placed by him in Mr Seeley’s hands. The latter, 
l1—2 
