Sept. 1 6, 1 8 So] 



NATURE 



469 



extra hands were taken in consequence of the heavy work entailed 

 by sounding during the night. All these men seemed to be well 

 conducled, as well as good sailors ; and although they had only 

 two meals a day, their physique was quite equal to that of our best 

 British seamen. Mr. Norman and I took with us as dredger a 

 steady and intelligent man, John Wilson ; and Prof. Marion had 

 his dredger, named Armand. These men were of great use in 

 sifting the material brought up by the dredges. For the Captain, 

 I can only echo the opinion e.xpressed by Prof. A. Milne- 

 Edwards in his Preliminary Report, that his arrangements were 

 first rate, and his skill admirable, especially considering that the 

 kind of work was new to him, and that he had not previously 

 made or even seen any deep-sea dredging. 



The members of the Commission assembled at Bayonne, and 

 the Travailleur arrived there on July l6th. The next morning 

 she went to sea, \\ ith all the party on board except the President, 

 who was obliged to return to Paris, and might also have justly 

 claimed exemption from active service, being in his eightieth 

 year. Until August 1st (with the exception of Sundays, the iStli 

 and 25th, which we spent at San .Sebastian and Santander) we 

 were hard at work sounding, dredging, and trawling. The 

 weather was very fine ; and the dreaded Bay of Biscay lost its 

 stormy character on this occasion. 



The principal object of the Expedition was to ascertain the 

 nature of the fauna which inhabits at considerable depths this 

 part of the Bay of Biscay ; and this object was thoroughly and 

 successfully accomplished. Twenty-three dredgings were made 

 for that purpose at depths ranging from 337 to 2600 metres, each 

 metre being about thirty-nine inches, or rather more than half a 

 fathom. The dredgings between 600 and 1,000 fathoms were 

 the most important. Every department of the Invertebrata was 

 well represented ; and novelties were discovered in MoUusca, 

 Crustacea, Echinoderms, Annelids, Actinozoa, and Sponges. 



As regards myself, this Expedition had a peculiar charm. 

 Having had the scientific charge of similar expeditions for the 

 Royal Society in H.M.S. Porcupine in 1869 and 1S70, and 

 in H.M.S. Valorous in 1S75, and having examined the 

 collections made during the voyages in H.M.SS. Sliearwater 

 and Challenger, as well as those made in nearly all the Swedish, 

 Norwegian, Dutch, and American deep-sea and exploring 

 expeditions in the North Atlantic, I was naturally glad to 

 participate in the French Expedition, and particularly as it 

 embraced that part of the sea which was at no great distance 

 from the scene of my former labours in the cruise of the Porcu- 

 pine sXowg the western coasts of Spain and Portugal, and which 

 cruise was so unu.-ually productive. Impelled by this recollection, 

 I made last year a verbal and informal application to the late 

 First Lord of our Admiralty for the use of one of Her Majesty's 

 ships to explore the Bay of Biscay this summer. The answer 

 I received was very favourable ; but the pecuniary resources of 

 our Government were then at a very low ebb, and I was en- 

 couraged to renew the application when commerce revived and 

 t'mes became, more prosperous. I hope our new Government 

 will avail itself of the now improved finances, and not neglect 

 this genuine and beneficial method of instructing the nation and 

 maintaining its credit for maritime discovery. 



The fauna observed during the Travailleur' s cruise closely 

 resembled that which I ascertained during the Porcupine cruise 

 in 1870 to exist at corresponding depths. This will be shown, 

 so far as the MoUusca are concerned, in the list of species 

 appended to the present paper ; and I have no doubt that the 

 other branches, when they have been worked out by the experi- 

 enced naturalists to whom they have been assigned, will confirm 

 my opinion. 



In a physical and geological point of view this French Expedi- 

 tion has borne good fruit. No less than 103 soundings were 

 made. They have proved the existence, within a few miles of 

 the coast, of a submarine valley opening from the Fosse de Cap 

 Breton and extending to a point opposite Cap Penas. The 

 large diagram and chart which I now exhibit will give a better 

 explanation than I can do by any words. The diagram was 

 prepared for me when I presented to the Royal Society my 

 Reports of the Porcupine Expeditions of 1869 and 1S70 ; and 

 the chart has been filled up and given to me by my kind friend 

 the Hydrographer. 



The striking inequalities of depth within a narrow area which 

 thus appear were noticed in a ISayonne newspaper of August 

 4th, as "des grands fonds sous-marins, qui continuent sous les 

 eaux de I'Atlantique les valle'es pyrcneennes." As a general 

 rule, it may be said that where mountains or high land approach 



the sea the depth of water is greater oft that coast than where 

 the land lies low. But this must depend in a great measure on 

 the geological nature of the land adjacent to the sea. If the 

 formation be granitic or gneissic, the wear and tear or denudation 

 must be slower than if the formation be sandstone. Cretaceous, 

 or Tertiary ; and the action of rivers and streams on'the surface 

 of the Land must be proportionally increased or decreased, and 

 must cause the sea-bed to be more or less filled up in the course of 

 time. Everywhere during the dredgings of the Travailleur in 

 deep water the sea-bed was found to be covered by a thick layer 

 of mud, of a different colour from that of the Atlantic ooze ; 

 and this mud has probably accumulated from untold ages by the 

 incessant efilux of the Gironde, tlie Adour, and numerous other 

 rivers and streams into the Bay of Biscay. As may be supposed, 

 the fauna which inhabits such mud is very scanty ; and it re- 

 quired a considerable amount of patience and perseverance to 

 extract a few organisms from the unpromising material. No 

 wonder that Dr. Carpenter «as discouraged, as a zoologist, by 

 what he termed " the singular barrenness of this deposit in 

 regard to animal life," when he described the Mediterranean 

 cruise of the Porcupine in 1870. 



Within a few days after the return of the Expedition Prof. A. 

 Milne-Edwards presented to the Academy of Sciences at Paris 

 a Preliminary Report of the zoological results of the Expedition, 

 which was published in the yournal Officiel dc la Republique 

 Francaise. As most of the departments of the marine Inverte- 

 brata have been so fully and carefully treated by him in this 

 Report, I will content myself with a few supplementary remarks 

 as to the MoUusca, which especially engaged my attention during 

 the cruise. At the request of Dr. Fischer, who will undertake 

 this department, and with the sanction of the President, I was 

 entrusted with all the more critical specimens of MoUusca: and 

 these specimens I have now cleaned, assorted, and compared 

 with my own collection from the Porcupine Expedition of 1870, 

 on the western coasts of Spain and Portugal. I subjoin a 

 complete list of the Travailleur MoUusca, distinguishing in 

 separate columns those species which are Porctipine, those which 

 were previously known to me from Norway or the Mediterranean 

 only, and those which I consider new to science. The total 

 number of the species in this list is 152, out of which 13S are 

 Porctipine, three only appear to be peculiarly northern, one 

 peculiarly southern or Mediterranean, and eleven new to science. 



The results, especially in the last -mentioned category, are most 

 noteworthy. They serve to show how little we know of the 

 deep-water MoUusca, when we reflect that the area of the sea- 

 bed lately explored in a short period of time, and in a necessarily 

 cursory manner, is but a very small corner of the Atlantic, and 

 that it would take many years to complete the exploration so 

 auspiciously commenced. The area traversed by the dredge during 

 this crui-e represents probably much less than a ten-thousandth 

 part of the sea-bed lying between Cape Breton and Cape 

 Penas ; and our means of exploration by the dredge are by no 

 means satisfactory, particularly on muddy ground, of which the 

 deep-water zone is mainly composed. Instead of our being 

 able to scrape a few inches of the surface of the sea-bed at 

 considerable depths, so as to collect in the dredge all the 

 animals which inhabit the superficial layer, we find too often, to 

 our disappointment, that the dredge, when it reaches the bottom, 

 sinks into the mud from its own weight and from the momentum 

 given to it by the motion of the ship, and that it then acts as a 

 subsoil plough, and not as a scraper. I must ask one of my 

 engineering friends to devise some instrument more efficient than 

 the modern dredge. 



Although it cannot be' positively stated that the abyssal zone, 

 or even the benthal zone, is inhabited only by certain species of 

 MoUusca, some species observed by me during the preparatory 

 excursion to Cap Breton and the Travailleur cruise bear out the 

 statement to some extent. For instance, A'ucula nitida, Dis- 

 c/iidcs bifissus, Rissoa abyssicola (a now inappropriate specific 

 name), and Defrancia decussata occurred only in the shallow 

 water excursion ; , while A'ucula corbuloides, Sipliodentalium olivi, 

 Pissoa deliciosa, and Defrancia hispidula, occurred only in the 

 deep-water cruize. 



Several deep-water species of MoUusca occurred in_ this 

 Expedition, which had been until lately supposed to be extinct ; 

 they are fossils of the Upper Tertiaries of Europe. For the 

 Geological definition of this term see "British Conchology," 

 vol. i. pp. 315. 316; 



A curious provision of nature — if we may in tliese pmto- 

 sophical days use such a phrase — was observable in the case of 



