Dec. 2, 1869] 
NATURE 
135 
THE DEEP-SEA DREDGING EXPEDITION 
IN “ELMS. “PORCUPINE” 
I.—NATURAL HISTORY 
Y part of the expedition in H. M. S. Porcupine com- 
menced on the 18th of May, and ended on the 13th 
of July last. It comprised the Atlantic coast of Ireland, 
from the Skelligs to Rockall (a distance of about 6} 
degrees, or 400 miles), Loughs Swilly and Foyle on the 
north coast, and the North Channel on the way to Belfast. 
I took with me as assistant Mr. B. S. Dodd (who had 
accompanied me in former dredging expeditions) ; and 
as dredger Mr. W. Laughrin, of Polperro, an old coast- 
guardman, and an Associate of the Linnean Society. Both 
did their share of the work carefully and zealously. 
The first dredging was on the 24th of May, about 4o 
miles off Valentia, in 110 fathoms ; bottom sandy with 
a little mud. The fauna was mostly northern, and the 
following are the more remarkable species there procured : 
Mollusca—Ostrea cochlear, Neera rostrata, Verticordia 
abyssicola, Dentalium abyssorum, Aporrhais Serresianus, 
Buccinum Humphreysianum, Murex imbricatus, Pleuro- 
toma carinata, and Cavolina trispinosa,; Echinodermata 
—Echinus elegans, Cidaris papillata, and Spatangus 
Raschi; Actinozoa—Caryophyllia Smithiz, var. borealis. 
Of these, Ostrea cochlear, Aporrhais Serresianus, and 
Murex imbricatus are Mediterranean species ; and 7yo- 
chus granulatus also imparted somewhat of a southern 
character, although that species was afterwards found 
living in the Shetland district. Ostrea cochlear is a small 
Mediterranean species of oyster; and it is one of the 
shells which Milne-Edwards noticed as adhering to the 
telegraph-cable between Sardinia and Algiers from a 
depth of about 1,100 fathoms. Although considered 
peculiar to deep water, I found it attached to the columns 
of the temple of Jupiter Serapis at Pozzuoli, which are 
reputed not to have been submerged to any depth. The 
above-mentioned results of this dredging will give a fair 
idea of the fauna inhabiting the 1oo-fathom line on the 
west of Ireland. 
After coaling at Galway we steamed south; “and (the 
weather being very coarse and unpromising) we dredged 
in Dingle Bay, at a depth of from 30 to 4o fathoms ; 
bottom rocky and muddy. As before, in comparatively 
shallow water, we had two dredges out, one at the bow, and 
the other at the stern ; this was what I always did in my 
own yacht, when dredging in from 20 to 200 fathoms. In 
Dingle Bay the dredges several times caught in rocks or 
large stones, but were saved by the usual yarn-stops, and 
by the extraordinary strength of the two-inch Chatham 
rope which was used. On one occasion, when the dredge 
was fast, the steamer, which was nearly of 400 tons burden, 
was pulled round, and swung hy the rope as firmly as if 
she were at anchor and moored by a chain cable. Here, 
again, the Mollusca were mostly northern. Szphonodenta- 
lium Lofotense, Chiton Hanleyi, Tectura fulva, Odostomia 
clavula, Trophon truncatus, and Cylichna nitidula fall 
within this category; and Ludima subulata, Trophon mu- 
ricatus, Pleurotoma attenuata, and Philine catena may be 
reckoned southern species. But the most remarkable 
shell obtained in this dredging was Montacuta Dawsoni, 
which I had described and figured from specimens found 
by Mr. Robert Dawson in the Moray firth. I subse- 
quently detected in the Royal Museum at Copenhagen 
specimens of the same species in the collection of Green- 
land shells, made by the late Dr. H. P. C. Moller. The 
species was briefly described or noticed by him in the 
addenda to his ‘ Index Molluscorum Groenlandie,’ as 
“ Testa bivalvis” ; but he did not give it any other name. 
The size of the Greenland specimens is considerably 
greater than that of British specimens, thus adding 
another to the numerous cases of a similar kind which I 
have from time to time adduced in illustration of the fact, 
that with regard to those species of Mollusca which are 
s 
common to northern and southern latitudes, and which 
inhabit the same bathymetrical zone, northern are usually 
larger than southern specimens. It may, perhaps, be a 
not unfair inference, that the origin of such species is 
northern, and that they dwindle or become depauperated, 
in proportion to the distance to which they have migrated, 
or been transported from their ancestral homes. 
The following week was occupied in sounding and dredg- 
ing off Valentia, and on the way to Galway, at depths vary- 
ing from 85 to 808 fathoms. The fauna throughout was 
northern. Several interesting acquisitions were made in 
all departments of the Invertebrata. Among the Mollusca 
I may mention—WNucula pumila (Norway), Leda frigida 
(Spitzbergen and Finmark), Vertécordia abyssicola (Fin- 
mark), Siphonodentalium quinguangulare (Norway and 
Mediterranean),and an undescribed species of sys allied 
to #. Sabint,; Echinodermata—Srisinga endecacnemos ; 
Actinozoa— Ulocyathus (or Phyllodesmia) arcticus. That 
fine sponge Phakellia ventilabrum was also met with so 
far south, in 90 fathoms. The 808 fathoms’ dredging was 
then a novelty, being the greatest depth ever explored in 
that way. The length of rope paid out was 1,100 fathoms, 
and the time occupied in hauling in was 55 minutes. The 
same proportional time was observed in other dredgings 
during my part of the expedition, viz. 5 minutes for every 
100 fathoms of rope. The dredge contained about 2 ewt. 
of soft and sticky mud, in appearance resembling ‘‘ China 
clay.” The animals brought up on this occasion were 
quite lively ; and I examined more than one specimen of 
a small Gastropod (described and figured by me as‘Lacuna 
zenella), which had very conspicuous eyes : there was also 
an active little stalk-eyed crab. 
The next cruise was for ten days, and comprised the 
examination of the sea-bed between Galway and the 
Porcupine Bank, as well as beyond the Bank, at depths 
varying from 85 to 1,230 fathoms. All the Mollusca were 
northern, except Aporrhais Serresianus; and even that 
I am now inclined to consider identical with 4. AZacandree, 
which inhabits the coasts of Norway and Shetland ; the 
latter appears to be a dwarf variety or form. The 
more remarkable species were, Limopszs aurita (a well- 
known tertiary fossil), Arca glacialis, Verticordia abysst- 
cola, Dentalium abyssorum, Trochus cinereus, Fusus 
despectus, F. Islandicus, F. fenestratus, and Colum- 
bella haligett, (a tertiary fossil), among the Mollusca ; 
Cidaris papillata and Echinus Norvegicus among the 
Echinoderms, and the beautiful branching coral, Lophohelia 
prolifera. In the deepest dredging made in this cruise 
(1,230 fathoms), occurred several new species and two 
new genera of the Arca family, Trochus minutissimus of 
Mighels (a-North American species) having two con- 
spicuous eyes, a species of Ampelisca (Crustacea) with 
the usual number of four eyes, comparatively gigantic 
Foraminifera, and other animals belonging to undescribed 
species and genera. An enormous fish (Mola masus), 
which is not uncommon on the coasts of upper Norway, 
was slowly swimming or floating on the surface of the 
sea; but we did not succeed in capturing it for want 
of a harpoon. 
We then put into Killybegs, county Donegal, and coaled 
there forour Rockall cruise. In anticipation of this cruise 
taking a clear fortnight, coals were stacked on the deck, 
in addition to the usual stowage in the bunkers, so as to 
provide a sufficient supply. Some delay was caused 
by the non-arrival of a proper galvanometer to work 
Siemens’ electro-thermometrical apparatus, which we were 
anxious again to try. We left Donegal Bay on the 
27th of June, and returned to the mainland on the 9th 
of July, after experiencing severe weather. The vessel 
sustained some injury from the heavy cross seas which 
struck her on her homeward passage. During this cruise 
we dredged seven days at depths exceeding 1,200 fathoms, 
and on four other days at less depths ; the greatest depth 
was 1,476 fathoms, In this last-mentioned dredging we 
