6 
one -fourth to the list of species of British shells, and it is believed that 
some other classes, as the Foraminifera, will be increased in a still larger 
proportion. In the case of species previously known there was no per- 
ceptible difference between individuals found in their ordinary habitat and 
those obtained from great depths. The Mollusca dredged off the west 
coast of Ireland resembled in some respects those found in the Mediter- 
ranean, and in others, Arctic forms ; a detailed report upon them will be 
found in Nature for Nov. 25 and Dec. 1, 1869. 
It appears, therefore, that a complete disproof has been furnished of the 
doctrine, that a certain amount of Bathymetrical pressure must be preju- 
dicial, if not absolutely fatal, to the higher forms of animal life. According 
to the well known hydrostatic law, the pressure of fluids is equal in all 
directions, and this pressure, however great, acting on an animal consisting 
entirely of solids and liquids, and containing no air cavities, can produce 
no alteration in its shape. Human beings are not conscious of the enor- 
mous pressure of the air on their bodies (14 lbs. per square inch), which 
in actual amount is greater than that upon many minute animals at great 
depths in the sea. Further, the direct experiment has been recently tried 
of subjecting living marine worms immersed in water to a pressure of 3 
tons per square inch (equivalent to a depth of 2,400 fathoms), which 
apparently had not the least effect upon them. 
In some dredgings Echinodermata were very abundant, in more than 
one instance many hundreds of specimens of the hitherto very rare 
Echinus norvegicus being obtained. In another locality, at a depth of 
about 500 fathoms, the dredges came up full of the beautiful branching 
coral, Lophohelia prolifera, specimens of which were presented to the 
Institution. In the 4 ' warm area " to be presently described, between the 
north of Scotland and the Faroe Islands, at a depth of about 600 fathoms, 
siliceous sponges of large size were found in extraordinary abundance, to 
which the generic name Holtenia had been given. Quitting the subject 
of the animal life, to which the attention of the speaker had only been 
casually directed in the intervals of his physical and chemical investiga- 
tions, he then described the temperature results obtained. 
The temperature of the sea at various depths was taken both by serial 
and bottom soundings, i.e., in some observations only the temperature at 
the bottom was ascertained, while in others a series of determinations 
were made at intervals of depth below the same spot at the surface, e.g., 
in depths up to 500 or 600 fathoms the temperature was determined at 
every 50 fathoms; at greater depths at every 100, 200, or 250 fathoms. 
