PROCEEDINGS OF SOCIETIES. 123 
to the President, that gentleman furnished the meeting with 
the following list of species observed by- him on the in- 
spection (cursory) of a few slides, and from which the rich- 
ness of the locality may be judged of. 
List oF SPecrIEs oF DIATOMS NOTICED IN Mupb FROM THE MENAI STRAITS 
Coscinodiscus radiatus. Pleurosigma angulatum. 
4a minor. Fe decorum. 
ne excentricus. 3 litorale. 
Eupodiscus sculptus. 5) distortum. 
3 Sulous. a ? 1. sp. 
45 CVASSUS. Grammatophora marinu. 
2 ee radiatus. pS serpentind. 
Actinocyclus undulatus. Melosira maculata. 
Actinophenia splendens. Orthosira arenaria. 
Triceratium favus. Biddulphia rhombus, 
> elliptica. 95 aurita. 
ie amphisbenda. ES turgida. 
Pleurosigma balticum. 
“On a peculiar Larve Form resembling Pluteus,” by Dr. 
Cobbold. (‘Trans.,’ p. 50.) 
~ “Directions for Making Spherules of Calcareous Salts, with 
some Observations on Molecular Coalescence,” by G. Rainey, 
Esq. (‘ Trans.,’ p. 41.) 
A discussion followed the reading of this paper. 
Professor Quekett stated that he had observed crystalline 
spherules in the urme of the horse, in a specimen which had 
been kept for many years in the Museum of the Royal Col- 
lege of Surgeons. 
Dr. Carpenter thought Mr. Rainey’s observations very 
important ; but he believed that in shells there was a true 
cellular structure. 
Dr. Lankester said that Mr. Rainey’s observations were 
interesting in connection with those made by Mr. Sorby 
on the physical causes producing the Oolitic structure in 
rocks. 
Professor Busk referred to an oolitic deposit in the lake of 
Mexico, which was produced, not by physical causes or spheru- 
lation, but by the deposit of caleareous matter on the surface 
of the ova of an insect which lived in the lake. The ova, 
when recent, were eaten by the natives; but those which 
were not taken for this purpose became cemented into a true 
oolitic petrifaction. 
