298 Mr. J. Grwyn Jeffreys on Dredging This genus has many characters in common Avith the genus Batrachoseps ; but it differs in the tail (which is twice as long as the body and head) being cylindrical and of the same dia- meter and subannulated appearance as the body and head, giving the whole animal the appearance of a Ccecilia or worm. OpMohatracJius vermicularis. Black. Length of the body and head 2J inches, of the tail 4J inches. Hob, Costa Eica (Osbert Salvin, Esq.). B.M. XXXVII. — Last Report on Dredging among the Shetland Isles. By J. GwYN Jeffreys, F.E.S.* This was my seventh expedition to the northern extremity of our seas, and occupied the whole of the summer. It was not so successful as those in some previous years, owing to the stormy state of the weather. While my friends in England, Wales, Ireland, and Scotland were enjoying calm sunshine, our climate was exactly the reverse ; and the persevering course of the wind (from north-west to south-west) prevented our doing much at sea. The North Sea is notoriously subject to broken weather, this being the point where the warm air in- duced by the Gulf Stream and westerly winds meets the cold air brought down by the arctic current. The fauna of the Shetland waters, however, is by no means exhausted. Every expedition has produced novelties, not only in the Mollusca, but in all other departments of marine zoology. On the present occasion I obtained, at a depth of 120 fathoms, a living specimen and a larger dead one of a fine species of Pleurotoma^ P. carinata of Bivona. It was origi- nally described as a Calabrian fossil ; and Searles Wood records a single specimen having been found in the Coralline and another in the Bed Crag. Professor Sars and Mr. M^ Andrew dredged a few specimens off the coasts of Norway ; and the former gave some interesting particulars of the animal, which I have been able to confirm by my own observation. Although allied to P. nivalis^ and found in the same locality, it has dis- tinct eyes placed on rather prominent stalks or ommatophores, whereas P. nivalis has no eyes nor any trace of eye-stalks. On this account Sars proposed the generic name Typhloman- gelia for the latter species ; but it must be borne in mind that Eulima stenostoma is also eyeless, and yet is closely related to * Communicated by the Author, having been read at the Noi*wich Meeting of the British Association, August 20, 1868. among the Shetland Isles. 299 its congeners and companions^ all of which have very con- spicuous eyes. It is a somewhat remarkable coincidence that the shell of E. stenostoma resembles a large Achatina acicula (a land mollusk), which is in the same category as regards these so-called organs of sight. The shells of P. carinata and P. nivalis are easily distinguishable. Among the rarer and more noteworthy mollusks procured this year were the following : — Montacuta tumidula. St. Magnus Bay and near Fetlar. Described by me from the Hebrides in the Reports of the Association for 1866. M. donacina^ S. Wood. A single valve from deep water in St. Magnus Bay. Another valve had been dredged by me at Falmouth in 1839. It is a rare Coralline Crag fossil. It nearest ally is M. suhstriata. Utriculus glohosusj Loven. A small living specimen oc- curred again in St. Magnus Bay. U. expansus^ Jeffr. A few young specimens also in St. Magnus Bay. Odostomia Warrenij Thompson. Never having seen this shell in a fresh and perfect state, I considered it (Brit. Conch, iv. p. 143) a variety of 0. ohliqua. But the discovery of live specimens in St. Magnus Bay and near Fetlar enables me to separate the two as distinct species. 0. Warreni has a shorter spire and more swollen whorls than 0. ohliqua^ the suture is deeper, the stride are much stronger at the base of the shell, the whole surface is covered with most delicate and close-set microscopic spiral lines, and the umbilicus is well de- veloped and deep. The animal of 0. Warreni has a peculiar foot ; this is not plain and rounded at its extremity, as in 0. ohliquay but is deeply bilobed or forked like the tail of a swallow. No other species of Odostomia^ so far as I am aware, has a similar foot. One individual spun a fine glutinous thread from the middle of the sole of the foot, and kept itself suspended for some time from the surface of the water, with the point of the shell downwards. I found a dead specimen of 0. ohliqua on the same ground with 0. Warreni. 0. umhilicarisj Malm. A young specimen from St. Magnus Bay, nearly globular, and thus exhibiting the same distinctive characters as the adult. Siphonodentalium Lofotense and Cadulus (or Loxoporus) suh- fusiformis again occurred, the former being more widely dis- tributed. Both inhabit the Mediterranean ; and the latter is a Sicilian and Viennese fossil. I had an excellent opportunity of observing them alive and in active motion. The thread- like and extensile organs by which the Solenoconchia seize their prey are unlike the tentacles of any Gastropod, and their 300 Mr. J. Gwyn Jeffreys on Dredging function is quite different. I would call these organs cap- tacula^ an appropriate word and not less classically formed than tentacula. Leda^ernula was again dredged in St. Magnus JBay ; but with it was a dead and apparently semifossil valve of Tellina calcarea. I must therefore hesitate in considering the one more than the other recent or an inhabitant of the British seas at the present time. Being in the south of Europe last winter I undertook the examination of the Mediterranean and Adriatic shells ; and the result greatly surprised as well as interested me. The dredg- ings of Capt. Acton (the Commandant of the Italian navy) in the Gulf of Naples, and the extensive collections of Dr. Tibcri at Portici, General Stefanis at Naples, Herr Weinkauf from Algeria, and of Dr. Brusina at Zara, especially yielded a vast quantity of new material for a comparison of the marine testacea of the north and south of Europe. Many of the species having been described (some insufficiently) under different names, the difficulty of identification is considerable ; but there is no doubt that a remarkable concordance exists, and to a great extent, between the mollusca which inhabit the deeper parts of the Atlantic and Mediterranean seas from 62° to 36° N. lat. The littoral kinds differ much more — a circumstance which may have been occasioned by climatal conditions. To exemplify the former proposition I subjoin a list of 75 species, usually considered northern, which are common to the North Sea and the Mediterranean, with their principal synonyms : — Names of Species. Synonyms. Terebratula caput-serpentis, Linne. Argiope lunifera, Philippi Terebratula cistellula, Scarles Wood. Crania anomala, Miiller Anomia turbinata, Poll. Pecten septemradiatus, Miill. Ostrea inflexa and O. clavata, Poli. P. aratus, Gmelin P. Bruei^ Payraudeau. P. Testae, Bivona P. furtivus, Loven. P. striatus, Mull. P. Hoskynsi, Forbes P. imbrifer, Lov. P. vitreus, Chemnitz P. Gemellarii-filii, Biondi. P. similis, Laskey P. pygmaeus, von Miinster. Lima Sarsii, Lov Perhaps L. crassa, Forbes. L. elliptica, Jeffreys. L. subauriculata, Montagu. Pinna rudis, L P. pectinata of some authors, not of Linne. Mytilus phaseolinus, Ph. Modiolaria discors, L. Nucula nitida, G. B. Sowerby. N. tenuis, Mont N. decipiens, PL Leda pygmaea, v. Miinst Probably Nucula negeensis, Forb. Area obUqua, Ph , A. Koreuii, Danielssen. among the Shetland Isles. 301 Names of Species. Synonyms. Lepton nitidum, Turton. Montacuta ferruginosa, Movd. Lucina borealis, L. Axinus Croulinensis, Jeffr. Cyamium minutum, Fahricim. Cardium minimum, Ph C. suecicum, Lov. Astarte sulcata, Da Costa Tellina fusca, Poll. Lucinopsis undata, Pennani, Venus incompta, Ph. Tellina balthica, L T. rubiginosa, Poli. T. pusilla, Ph. Scrobicularia nitida, Miill. Syndesmya intermedia, Thompson. Lyonsia Norvegica, Ch Pandorina coruscans, Scacchi. Thracia convexa, W. Wood T. ventricosa, Ph. Neaera rostrata, Spengler N. attenuata, Forh. Xylophaga dorsalis, Turt. Siphonodentalium Lofotense, Sars. S. quinquangulare, Forh S. pentagonum, Sars. Cadulus subfusiformis, Sars. Chiton Hanleyi, Bean. C. cancellatiis, G. B. Sow. C. cinereus, L C. asellus, Sp. C. Isevis, Mrnit C. corallinus, Risso. Tectura virginea. Mull. Propilidium ancyloides, Forh. Scissurella crispata, Fleming S. aspera, PA., var. Trochus cinerarius, i., var. variegata. Rissoa reticulata, Mont R. Beanii, Hanley. R. cimicoides, Forh R. sculpta, F. 8f jff., not of Philippi. R. Zetlandica, Mont. R. abyssicola, Forh. R. parva, Mont, and var. interrupta R. obscura and R. simplex, Ph. R. inconspicua, Alder. R. albella, Lov R. Oenensis, Brusina. R. vitrea, Mont. Jeffrey sia diaphana, Aid. Rissoa ? glabra. Aid., not of Brown. J. opalina, Jejr. Scalaria Trevelyana, Leach. Aclis Walleri, Jefr. Odostomia clavula, Lov. O. albella, Lov. O. umbilicaris. Malm. O. conspicua. Aid. O. Scillse, Scacchi. O. nitidissima, Mont. Eulima bilineata. Aid. Natica catena, Da C. Probably Nerita helicina, Brocchi. Velutina laevigata, Penn. Ceritbium metula, Lov Mediterranean ,j^cfe Hanley ; perhaps Cerithiopsis Barleei. Purpura lapillus, L. Trophon Morchi, Malm Bela demersa, Tiheri. Bulla utriculus, Brocchi B. Cranchii, Leach. Philine scabra, Miill BuUsea angustata, Biv. Aplasia punctata, Cuvier A. hybrida, J. Sozverhy. Spirialis retroversus, Fl. Scsea stenogyra, Ph. ; oceanic. Clio pyramidata, L Oceanic. Ann. & Mag. N. Hist. Ser.4. VolAi, 21 302 Mr. J. Gwyn Jeffreys on Dredging How is this concordance to be accounted for ? I have care- fully read again Forbes's elaborate essay '^ On the Connexion between the distribution of the existing Fauna and Flora of the British Isles, and the Geological changes which have affected their area, especially during the epoch of the Northern Drift " (Memoirs of the Geological Survey of Great Britain, vol. i. 1846) ; but I cannot find in it a satisfactory solution of the question. He, indeed, mentions the continuance of some " arctic" species in the British seas, the rest having "retired for ever," and that certain other species which he called " Boreal or Celtic " occurred in a fossil state in Sicily ; and he states (p. 390) that " in the deepest of the regions of depth in the ^gean " the same representation of a northern fauna as exists in our own seas is maintained, " partly by identical and partly by representative forms." The instances he gives do not support such a view ; and I am not a believer in " repre- sentative forms." He evidently was not aware of the fact that boreal (not arctic) species still live in the Mediterranean. I, however, fully agree with him that at some former time (which he designates "the newer pliocene epoch") there was an open communication between the Atlantic (according to him the "North Seas") and the Mediterranean, by which the fauna became diffused. I should be inclined to place the Atlantic point of communication at Bordeaux, and that of the Mediterranean at Narbonne, in the line of the Languedoc Canal, which extends from one coast to the other, and is very little above the present level of the sea. This communication must have been very wide ; and it remained open during the glacial epoch, which affected not only the north of Europe but also Naples, Sicily, and probably Ehodes. Dr. Tiberi showed me a fine valve of Pecten Islandicus which had lately been fished up in the Gulf of Naples at a depth of 50 fa- thoms, and with it a valve of P. opercularis quite as large as northern specimens ; both the valves were in a semifossil state, and the former was covered with the same Greenland species of Spirorhis {8. canceUatus, Fabr.) as I noticed on valves of P. Islandicus dredged in the Shetland seas at depths varying from 75 to 170 fathoms. Sir Charles Lyell has not adverted, in the last edition of his '■ Principles of Geology,' to the re- markable occurrence of such glacial fossils in the Shetland sea-bed, to which I called the attention of geologists in my former Reports as well as in the 2nd volume of ^ British Con- chology,' p. 58 ; and he seems to have strangely overlooked the observations of Philippi and Seguenza on the fossils of Calabria and Sicily, when he stated (Princ. Geol. i. p. 298) that " deposits filled with arctic species of marine shells are to among the Shetland Isles. 303 be seen in full force on the North American continent ten or more degrees further south than in Europe." Possibly he was misled by one of Forbes's conclusions (Rep. GeoL Surv. p. 402), that " no glacial beds are known in Southern Europe." This, however, was more than twenty years ago. I have myself identified from the Calabrian and Sicilian deposits several high-northern shells (e. g. Terehratula cranium^ T, sep- tatttj Lima excavata^ Mytilus modiolus^ Gyprina Islandica^ Mya truncata^ var. TJddevallensis^ Saxicava Norvegica^ Puncturella Noachinaj Emarginula crassa^ Buccinum undatum^ and Natica affinis or clausa)^ and from the Rhodian deposits Terehratula septata and Lima Sarsii. My old companion, Mr. Waller, picked up on the beach in a small bay on the west coast of Shetland a shell of Spirula australis. It is a tropical Cephalopod, and is not unfrequently thrown up by the waves on the southern and western shores of England, Wales, and Ireland, together with exotic species of Teredo J lanthina^ and Hyahea brought from southern latitudes. Dr. Morch informs me that several shells of the Spirula have this year been found in the Faroe Isles. The transport of such tropical productions to northern latitudes has been usually attributed to the Gulf-stream. It now, however, appears more probable that this is the consequence, not of the direct action and course of the Gulf-stream, but of the prevalence of westerly and south-westerly winds, which waft onwards to northern latitudes, in a northerly and north-easterly direc- tion, the floating objects carried to a certain distance by the Gulf-stream. The direct course of the Gulf-stream has not been observed further north than about 45° N. lat. ; from that point it would seem to dwindle into a north-easterly surface drift. A chart will shortly be published by the Admiralty in explanation of this view of the case ; and the following papers on the subject ought to be consulted by physical geographers : — Dr. Stark " On the Temperature of the Sea around the coasts of Scotland during the years 1857 and 1858, and the bearing of the facts on the theory that the mild climate of Great Britain during winter is dependent on the Gulf Stream " (Trans. E,. S. Edin. 1859), and Capt. Thomas's tables and re- marks in Mr. Alex. Buchan's Report " On the Temperature of the Sea on the Coast of Scotland " (Journ. Scottish Meteor. Soc. Oct. 1865). See also ' Br. Conch.' vol. i. (Introd.) pp. xcviii and xcix. I will add a short summary of the observations recorded in my Reports on Shetland dredgings and in the work last cited. 1. The bathymetrical zones have been too much divided by Risso and subsequent authors. There are two principal zones, 21* 304 Mr. J. Gwyn Jeffreys on Dredging littoral and submarine ; the nature of the habitat and the sup- ply of food influence the residence and migration of animals, not the comparative depth of water. Psammohia costulata and Buccinum undatum are instances in support of this proposition. 2. Specimens or varieties of the same species are larger in the littoral and laminarian zones than in deeper water : e. g. Mactra solida and its variety ellijptica^ Solecurtus candiduSj Pandora incequivalvis and its variety ohtusa or pinna^ Chiton Icevis^ Tectura virgineaj Trochus zizyphinuSj Pleurotoma Icevi- gata^ and Philine aperta. 3. The size of North-European specimens is usually greater than that of South-European specimens of the same species : e. g. Pecten s&ptemradiatuSj P. opercularis^ Lima hians^ My- tilus AdriaticuSy Isocardia cor^ Astarte sulcata^ Venus exoleta^ V. lincttty Tellina halaustina^ Chiton Hanleyi^ Tectura virgineaj NaticaAlderij Defrancia teres^D. purpurea jSmd Bulla utriculus, 4. The colour of specimens from the greatest depths is not less vivid than of those from shallow water, although each zone has colourless specimens. Venus ovata, Trochus zizy- phinusj Turritella terehra^ and Eulima hilineata may be men- tioned as examples. 5. Mollusca inhabiting deep water have consequently a larger supply of oxygen for the aeration of their gills than those which live in shallow water. See my account of Colum- hella halimeti, 6. The occurrence of the same species in the North Sea and the Mediterranean results partly from former geological or cosmical conditions, and partly from a communication which once existed between the Bay of Biscay and the Gulf of Lyons. 7. Exotic and oceanic shells are carried northwards by west- erly winds, and not directly by the Gulf-stream, which does not reach our coasts. 8. Land and freshwater mollusca are scarce in Shetland, owing to the scantiness of succulent vegetation for their food, and of lime for the construction of their shells. These are smaller than southern specimens ; and the same fact is obser- vable with respect to Shetland insects. 9. Semifossil shells of arctic species (such as Pecten Islandi- cuSj Tellina calcarea, Mya truncata^ var. Uddevallensisj Molleria costulata^ Trochus cinereus^ and Trophon clathratu^) are met with on the sea-bottom at considerable depths, and at some distance from land. The only explanation I can ofler is a former elevation of the sea-bed whereon these mollusks lived (and which was probably in shallow water), and its conversion into dry land, and a subsequent subsidence. Perhaps the sea- bed is still sinking. among the Shetland Isles. 305 10. Species recorded from the Coralline Crag and earlier deposits, and supposed to be extinct, have now been discovered living in the Shetland seas ; e. g. Limopsis aurita^ Pleurotoma carinata^ and Columhella haliceeti. Possibly Trochus amahilis is another case, assuming that it originated from Margarita ? maculata of Searles Wood. Professor Dickie has been good enough to report on some Diatoms from the insides of a quantity of Echinus NorvegicuSj which were dredged at a depth of 78 fathoms about forty miles from the east coast of Shetland. He says they are chiefly Navicula didyma^ Coscinodiscus excentricus^ C. minor j Acti- nocyclus undulatus, and Melosira sulcata^ with fewer of M, nummulo'ides and Nitzschia angularisj all marine ; also a few freshwater Cocconema lanceolatum^ Sinciella minuta^ and fragments of a Finnularia, And he adds that long ago he re- corded the occurrence of freshwater kinds of Diatomaceas mixed with marine kinds from the stomachs of Ascidice taken in deep water off Aberdeen. The freshwater Diatoms must evidently have been carried by a stream into the sea, and transported by the tide to the place where they sunk to the bottom, and were swallowed by the indiscriminating Echini and Ascidice. Diatoms inhabit the surface only of the water ; and Glohigerina and other Foraminifera not of a fixed or sessile nature have been observed by Major Owen to float when alive within a few inches from the surface. Dr. Wallich found the microscopic organisms which he called coccospheres " profusely in a living, or perhaps it would be more safe to say a recent, condition in material collected at the surface of the open seas of the tropics." Coccospheres and free Foraminifera cover the bed of the Atlantic at enormous depths. The occur- rence, therefore, of such organisms on the floor of the ocean at great depths does not prove that they ever lived there. I should rather be inclined to believe that they dropped to the bottom of the sea when dead or after having passed through the stomachs of other animals which had fed on them. A few small fishes were caught in the dredge at depths of from 90 to 100 fathoms. Dr. Gunther reports that they be- long to the undermentioned species : — Callionymus maculatus (Bonap.), Gohius Jeffrey sii (Gunth.), young, Cyclo;pterus lumpus (L.), young, Lejjadogaster himaculatus (Penn.), and Rhombus Norvegicus^ (Gunth.), young. He remarks that the last-named species is new to the British fauna, having been hitherto known from the coast of Norway only. Mr. Nonnan will report on the Crustacea, Echinoderms, and Sponges, Dr. M'Intosh on the Annelids, and Mr. Waller on the Foraminifera. 306 Mr. J. Gwyn Jeffreys on Dredging Mollusca inhabiting the Shetland Isles and the adjacent seas. (See Tables of distribution in ^ British Conchology,' vols, i.-iv.) Name of Species. MARINE. Bbachiopoda. Terebratula cranium, Miiller . . caput-serpentis, Linne tTerebratella Spitzbergensis, Da- vidson fRhynclionella psittacea, L Argiope lunifera, Philippi Crania anomala, Miiller