PROCEEDINGS OF SOCIETIES. 237 
From the foregoing considerations it seems natural to conclude 
that details too minute to be seen, may perhaps be made out by 
photography, and especially by those photographic processes 
which employ almost exclusively rays beyond the violet, rays 
ranging in wave-lengths from 0°03 to 0°04. The well-khown 
photographic experiment of Mr. Wenham on the honeycombed 
markings of Plewrosigma angulatum seems to verify this anticipa- 
tion. 
But whether these particular expectations shall come to any- 
thing or not, the circumstance that subjects well worth inquiry 
are continually presenting themselves, when we use a convenient 
set of measures, will surely be held sufficient to recommend 
their adoption by every member of the Club. 
ManNcHESTER LITERARY AND PHILOSOPHICAL SOCIETY. 
MICROSCOPICAL AND NATURAL HISTORY SECTION. 
January 7th, 1867. 
A. G. Latuam, Esq., President of the Section, in the Chair. 
The President exhibited mounted specimens of Foraminifera 
from Dogs Bay, Roundstone, and from Berwick Bay, and he re- 
marked on some differences in the character of the two deposits. 
He pointed out that in the Dogs Bay sand the prevailing forms 
are Truncatulina and Miliolina, while in the Berwick Bay dredg- 
ing they are Dentalina and Biloculina. He also remarked on the 
great difference in the quality of the shell of Truncatulina from 
these two localities, those from Dogs Bay being delicate and 
hyaline, while those from Berwick Bay are opaque and very thick 
and strong. 
The following paper, “ On Polymorphina tubulosa,’ was read 
by Dr. Alcock. 
In the course of examinations of the Dogs Bay sand I have col- 
lected great numbers of detached branches of Polymorphinatubulosa, 
a form of foraminifer which is not likely ever to be found perfect 
in shore sand. I have, however, met with several fine specimens 
of it with only the tips of the branches broken away; but the 
most interesting examples are some which are more damaged, and 
show several structural features difficult, if not impossible, to be 
seen in perfect specimens. The main body of the shell of Poly- 
morphina tubulosa has the form of Professor Williamson’s -P. 
communis, and appears to be identical with it, this form only, so 
far as I have seen, taking on the peculiar final development cha- 
racteristic of P. tubulosa. It consists in the mature state of the 
rounded shell of P. communis more or less concealed by several 
covered passages commencing at the mouth and taking a direction 
towards the base of the shell. These passages have their arched 
