—— 
136 
NATURE 
| Dec. 2, 1869 
got several living Mollusca and other animals, a stalk-eyed 
crustacean with two prominent and unusually large eyes, 
and an Echinoderm of the Holothuria family, of a blue 
colour. The bottom, atthe greatest depths, consisted of a 
fine clayey mud, which varied in colour (in some dredgings 
being brownish, in others yellow, creamcolour, or drab, 
and occasionally greyish), and invariably having a greater 
or less admixture of pebbles, gravel, and sand. The 
upper layer formed a flocculent mass, which appeared to 
be animal matter in a state of partial decomposition. 
This was in all probability derived from the countless 
multitude of Sa/s@z, oceanic ydrozoa, Pteropods, and 
other gelatinous animals, which literally covered the 
surface of the sea, and filled our towing net directly it was 
dipped overboard. Their remains must fall to the bottom 
after death. Such organisms doubtless afford a vast store 
of nutriment to the inhabitants of the deep. It must be 
borne in mind that it is extremely difficult to dredge in 
very deep water. The dredge must be unusually heavy 
to counterbalance the tendency of the necessary bulk 
of rope to buoy it up under the descending pressure ; 
and when it reaches the bottom, it sinks by its own weight, 
like an anchor, into the mud. This would give only 
the same result as the cuplead or any sounding machine, 
but on a larger scale; and it would tell us very little 
about the fauna. Further, if by the drift-way of the vessel, 
or by a few turns of the engine now and then, we are 
enabled to scrape the surface of the sea-bed, the dredge 
gets choked up with the flocculent mass above described. 
The fertile ingenuity of our experienced and excellent 
commander devised a method which was a great improve- 
ment in deep-sea dredging, and which enabled us to 
obtain at least a sample of the substratum. This was to 
attach two iron weights, each of 100 Ibs., to the rope, at a 
distance of 300 or 400 fathoms from the dredge (when the 
depth ex¢eeded 1,200 fathoms), so as to dredge trom the 
weights instead of from the ship, the angle thus made 
‘causing the blade of the dredge to lie in its proper position : 
in fact it reduced the depth by the distance of these weights 
from the vessel to the easy and manageable limit of 300 
or 400 fathoms. Another method was to fasten the bag 
to the dredge in such a way that, when it was hauled in 
it could be unlaced, emptied, and afterwards washed quite 
clean. I was thus assured that the specimens really 
came from the place where each dredging was made, and 
the risk of intermixture with previous dredgings was 
avoided. My sieves were also framed with a similar 
object, every sieve having a beading round the inside rim, 
to prevent specimens remaining inside the edges when 
the sieves were washed after every dredging. Two 
other kinds of sieve I also found useful. One was 
spherical, with its lid fastened inside by bolts ; its frame 
consisted of a strong network of copper ribs, which was 
lined with very fine gauze-wire of the same metal ; and it 
had a ring through which a rope would pass. Its use was 
to sift and wash away in the sea the impalpable mud got 
in such quantities at great depths, so as to leave only for 
examination all organisms exceeding in size =; of an inch, 
this being the greatest diameter of the wire-mesh in the 
lining. Some of the residuum or strained mud was like- 
wise preserved after sifting the material in the usual way. 
This apparatus, which we called the “globe-sieve,” saved 
a great deal of the time and useless labour required for 
washing that sort of dredged material through the ordinary 
sieves in a tub of sea-water, which would immediately 
become so turbid that, unless the tub were continually 
emptied and refilled, it was extremely difficult (if not im- 
possible) to detect any specimens. Another kind of sieve 
had a similar framework ; but the body was semi-globose, 
with a funnel-shaped neck. It was fastened to a long 
pole, and served for catching Pteropods, Sa/f@, and other 
animals on the surface of the sea. This went among us 
by the name of the “vase-sieve.” We tried on this and 
other occasions a contrivance of Mr. Easton, the cele- 
brated engineer, consisting of gutta percha valves, which 
closed inwards in a wedge-like form, and were fitted to 
the mouth of the dredge. The object was to retain the 
contents of the dredge while it was being hauled in, as I 
had found by frequent and disappointing experience that 
a large portion of the contents generally escaped through 
the mouth during this part of the operation. The con- 
trivance, although admirable in a theoretical point of 
view, was found impracticable; perhaps it may yet suc- 
ceed after more trials, and with some alterations. In their 
present form the valves close the mouth of the dredge, so 
that it has no contents to be retained. The deep-sea 
dredgings in this cruise yielded no end of novelties and 
interesting results in every department of the Invertebrata. 
They were enough to take one’s breath away. Among 
the Mollusca were valves of an imperforate Brachiopod 
with a septum in the lower valve, which I propose to 
name Cryptopora gnomon. Some shells were of a 
tolerable size; and the fry of Zsocardia cor (Kelliella 
abyssicola of Sars) were not uncommon. Many Crustacea 
(Amphipoda) were scarlet, and others bright red with 
feathered processes of a golden colour at the tail. A 
magnificent Annelid was pinkish, with purplish-brown 
spots on the line of segmentation. A Holothuria, from 
1,443 fathoms, was 5 inches long and 2} in circumference. 
None of the animals, especially the Mollusca, were living 
when they were brought on board and examined ; this was 
perhaps owing to the great change of temperature (some- 
times as much as 20°) between that of the sea-bed and 
that of the atmosphere. 
But to return from the bottom to the surface. At a 
distance of from 130 to 140 miles from the nearest part of 
the Irish coast I observed quantities of floating seaweed 
(mostly /wcus serratus) and feathers of sea-fowl, covered 
with Lefas fascicularis, and occasionally LZ. szdcata; and 
on the seaweed were also two kinds of sessile-eyed Crus- 
tacea. The wind having been previously easterly, it is 
difficult to say what share the wind or tide had in the 
drift ; but it did not appear to have been caused by any 
circulation from the equator. The fauna nowhere showed 
the least trace of that wonderful and apparently restricted 
current known as the Gulf Stream. The beautiful Pteropod, 
Clio pyramidata, flitted about in considerable numbers; a 
delicate cuttle-fish (Leachia ellipsoptera), which is supposed 
to prey on Sa/f@, was caught in the vase-sieve, as well as 
several specimens of a small and very slender pipe-fish or 
Syngnathus, One peculiar feature of this cruise was Rock- 
all, an isolated and conical excrescence of the Atlantic, 70 
feet high, and situate at least 200 miles from the nearest 
land. We lay to within a quarter of a mile of it on the 
evening of Saturday the 3rd of July, when fishing parties 
were formed, and continued their sport till midnight. 
The supply’of fresh fish thus procured was very accept- 
able. The rock was inhabited by a multitude of sea-fowl ; 
and a huge gannet perched on the highest pinnacle, 
looking like a sentinel, or the president of the feathered 
republic. On our return to Ireland, we dredged in Lough 
Swilly, Lough Foyle, and the North Channel, on the way 
to Belfast, where we arrived on the 13th of July. Here I 
parted with my shipmates and excellent companions, and 
enjoyed the hospitality and sympathy of my friends Pro- 
fessor Wyville Thomson and Mr. Waller. 
After my part of the expedition was concluded, I went 
for the second time to Scandinavia, and compared notes 
with Dr. Koren at Bergen, Prof. Sars (now, alas! no 
more) at Christiania, Prof. Lovén at Stockholm, Prof. 
Lilljeborg at Upsala, Prof. Torell at Lund, Prof. Steenstrup 
and Dr. Mérch at Copenhagen, and with Prof. Mébius 
and Dr. Meyer at Kiel. All these zoologists had investi- 
gated the Mollusca in the Arctic and North-European 
seas ; and the result of my interviews with them, and of 
examining the extensive collections in the public museums 
at the above places, was extremely useful in connection 
with the subject of the present report. 
