520 EXISTENCE OF SPECIES AT GREAT SEA-DEPTHS. 
alludes to the species as being only met with at great depths, that is 
to say, from 50 to 60 metres (164 to 197 feet). Associated with 
these three acephalous mollusks, were two gasteropods belonging to 
species of rare occurrence in localities usually explored by zoologists. 
One is the Aonodonta limbata; the other, Fusus lamellosus. The 
shell of this latter, characterised by the fine strize which traverse the 
whorls, was in a perfectly fresh condition, and contained, equally with 
the monodonta, the soft parts of the animal. These mollusks, it is 
therefore evident, were living at the spot from which they were 
obtained. 
. The corals living at these great depths offer still more interest. 
Those procured, number fourteen examples, belonging to three species 
of the Turbinolidee. One does not appear to me to differ in any res- 
pect from the Caryophyllia arcuata, a very rare species, met with in 
the fossil state in the Upper Tertiary deposits of Castel Arquato, 
Piedmont, and which occurs likewise at Messina. Another species 
of the same genus, closely related to C. clavus but which is yet dis- 
tinct, and so may be designated as C. electrica, seems to be much more 
abundant in the sub-marine valley in which the cable reposed, since 
I found ten individuals attached to the wire and bearing evident marks 
of having been developed upon this. I should add that this small 
species appears to be identical with a fossil coral of the Pliocene sub- 
division, discovered by M. Deshayes at Donera in Algeria. I am not 
able to refer to any established genus a third form of the Turbinolide, 
which was also attached to the same portion of the cable. This little 
coral, about one centimetre in length, does not exhibit the central 
axis of the Caryophyllig. It seems to occupy an intermediate position 
between the genera Ceratotrochus and Sphenotrochus. I propose for 
it the name of Thalassiotrochus telegraphicus, to recall at one and the 
same time, its zoological affinities, its open-sea habitat, and the cir- 
cumstances which led to its discovery. Finally, I should observe that 
to the same portion of the cable was attached a little branch of 
Bryozoons of the genns Salicornaria (8. Farciminiodes) ; and also 
several Gorgonid@, and two species of Serpul@. The calcareous tubes 
of the latter were of some size, and soldered to the wire along a con- 
siderable length. ‘The serpulee of the Mediterranean are too imper- 
fectly known, however, to allow these annelids to be specifically 
determined, but I believe they may be referred to two distinct species. 
We thus perceive that at the bottom of a part of the Mediter- 
