• • • - . PRESENTED The Trustees THE BRITISH MUSEUM. A / tf NATIONAL ANTARCTIC EXPEDITION >- - 1901-1904 NATURAL HISTORY VOL. III. ZOOLOGY AND BOTANY (INVERTEBRATA : MARINE ALGAE, MUSCI) LONDON -. PRINTED BY ORDER OF THE TRUSTEES OF THE BRITISH MUSEUM. 1907 (All Rights Reserved) SOLD BY LONGMANS AND Co., 39 PATERNOSTER Row, E.G. ; BERNARD QUARITCH, 15 PICCADILLY, \V. ; DULAU AND Co., 37 SOHO SQUARE, W. ; AND AT THE BRITISH MUSEUM (NATURAL HISTORY), CROMWELL ROAD, LONDON, S.W. PREFACE. WHEN, in 1901, the Expedition of the S.S. ' Discovery,' under Captain Scott, R.N., was sent to the Antarctic Regions, the Trustees of the British Museum gave their assistance to this national enterprise by allowing the cases containing the natural history specimens which might be obtained by the Expedition to be sent to the Natural History Museum for unpacking and sorting. They further undertook to publish a detailed report on the collections so obtained, under the superintendence of the Director of the Natural History Departments. Some of the most important collections have been dealt with by naturalists who were members of the Expedition. Thus, the Mammals and Birds are described by Dr. Edward A. Wilson, the Isopoda and Pycnogonida by Mr. T. V. Hodgson, and the Rocks (in relation to Field Geology) by Mr. H. T. Ferrar. Other groups have been dealt with by members of the staff of the Natural History Departments of the British Museum : Mr. Boulenger describes the Fishes ; Mr. E. A. Smith, the Gastropoda, Lamellibranchia, and Brachiopoda ; Mr. Jeffrey Bell, the Echinoderma ; Dr. Caiman, the Crustacea Decapoda, and the Cumacea ; Mr. Kirkpatrick, the non- calcareous Sponges; whilst Mr. G. T. Prior has prepared a petrographical description of the Rock-specimens. It has been necessary to obtain the assistance of other specialists in order to deal with the rest of the collections. So far as the latter group of contributors is concerned, the following is a list of the subject-matters, together with the name of the naturalist who has undertaken the work in each case :— EMBRYOS OF SEALS ANATOMY OF EMPEROR PENGUIN TUNICATA .... CEPHALODISCUS . CEPHALOPODA N0DIBRANCHS AND PxEROPODS POLYZOA . EGGS AND YOUNG OF ASTERIAS AMPHIPODA SCHIZOPODA NEBALI.E .... OSTRACODA COPEPODA . DR. MARRETT TI.MS. MR. W. P. PYCRAFT. PROF. HERDMAN. DR. RIDKWOOD. DR. HOYLE. SIR CHARLES ELIOT, K.C.M.G. MR. H. W. BURROWS. PROF. MAI/BRIDE. MR. A. o. WALKKU. MH. HOLT. DR. J. TIIIKLK. PROF. BRADY. DR. AVnl.KKNDEN. jv PREFACE. CIKRIPEDIA PROF. GRUVEL. MY/OSTOMA . . . PROF. v. GRAFF. ACAKI ....... DR. TROUESSART. COLLKMISOLA PROF. CARPENTER. POLYCH^TA PROF. EHLERS. GEPHYRIA MR. A. E. SHIPLEY. CH.KTOCXATHA .... . DR. FOWLER. XKMKKTINES ...... PROF. HUBRECHT. FREE PLATYHELMINTHES . . . MR. F. F. LAIDLAW. ( 'KSTODA ....... MR. A. E. SHIPLEY. NEMATODA ...... DR. v. LINSTOW. ZoANTHARIA MR. CLUBB. AlA'YONARIA AND PfiNNATULIDA . . . PROF. HlCKSON. HYDROMEDUS/E ...... MR. E. T. BROWN. CALCAREOUS SPONGES ..... MR. FREWEN JENKIN. RADIOLARIA ...... MR. LEWIS H. GOUGH. MOSSES ....... M. JULES CARDOT. LICHENS ....... MR. DARBISHIRE. AI.U.K (.MARINE) ...... MRS. GEPP. ALG.-E (FRESH-WATER) ..... DR. FRITSCH. ALG^E (CALCAREOUS) ..... DR. FOSLIE. PHYTOPLANKTON . . . . / . . DR. LEWIS H. GOUGH. The work of securing the assistance of these specialists and of distributing the collections has been performed by Mr. Jeffrey Bell, of the Zoological Department, who lias also acted as sub-editor of the Zoological and Botanical portions of the reports. The Keeper of .Minerals, Mr. Fletcher, has superintended the reports in the subjects belonging to his department. The Director desires to acknowledge the ability and energy which have been brought to bear on the preparation of the Zoological reports by Mr. Jeffrey Bell. Owing to his care, the reports have been got ready by the various contributors and published within a reasonable time after the return of the 'Discovery' from the \ntaivti.- bV'j'iiitis. Neither trouble nor expense has been spared in order to render tin- illu-l ration and presentation of the Natural History of the Expedition worthy of the generous dibits both of Captain Scott and his fellow-explorers and i if those who |irovided the funds for that enterprise. K. KAY LANKESTER. I'.HIi;. CONTENTS OF VOL III. ON COLLECTING IN ANTARCTIC SEAS. By Mr. T. V. llm.osox, F.L.S. . (10pp.) MOLLUSCA. VI.— PTEROPODA. By Sir CHARLES FLIOT, K.('.M.G.: LL.D. . (15 pp., 2 Pis.) ARTHROPODA. (A) CRUSTACEA. III.— AMPHIPODA. By Mr. A. 0. WALKER, F.L.S. . . (39 pp.. 1 :'> Pis.) IV. — LEPTOSTRACA. By Dr. J. THIELE . . . . (2 pp., 2 Figs.) V.— USTKACODA. By Prof. G. S. BRADY, F.R.S. . (9 pp., 3 Pis.) VI. — CIRRIPEDIA. By Prof. GRUVEL ...... (4 pp., 1 PI.) (B) PYCNOGONIDA. By Mr. T. V. HODKSON, F.L.S. . . (72 pp., 10 PI.) (C) ACAPJ. By Dr. TROUESSART . . (fi pp., 1 PI.) CHAETOGNATHA. By Dr. FOWLER . . (G pp.. 1 Chart) NEMATODA. By Dr. v. LINSTOW . (4 pp., 1 PI.) CESTODA. By Mr. ARTHUR E. SHIPLEY, F.R.S. . (G pp., 1 PI.) COELENTERA. I. — ALCYONARIA. By Prof. HICKSON, F.R.S. . (15 pp.. - I Ms.) II.— HYDROID ZOOPHYTES. By Prof. HICKSON, F.R.S., and Mr. F. II. < in AVKI.Y (34 pp., 4 Pis.) 111.— TENTACLES OF A SIPHONOPHORE. By Dr. HKNNIE . . (:: ]>p.. 5 Fiy snow, it forms an opaque covering over the sea bottom through which no light can penetrate, COLLECTING IN ANTARCTIC SEAS. 5 hence vegetable life to which light is essential is reduced to the minute forms pertaining to the Plankton. A large Laminarian was dragged up by the anchor in Arrival Bay and was unfortunately thrown away ; this was the only seaweed found within ten miles of the ship. A quantity of red Alga) was found off the shore of Tent Island, and more again at Cape Eoyds. Bepeated dredgings inside the 20-fathom line in Winter Harbour produced nothing whatever in the way of seaweeds, and dragging in Arrival Bay for Laminaria, carried out because it had once been found there, was equally unsuccessful. As soon as the Sound was frozen over the biological work was carried on through holes in the ice. It was soon found that these holes had to be made large, and at the beginning they were about six feet square. The ice taken from them had to go somewhere, and as any irregularity of surface caused drift to accumulate, the blocks were placed to windward and built up as a wall. In a comparatively short time this developed into a circular shelter some fifteen feet in diameter and six to ten feet high, having a small entrance to leeward. As one could work in perfect comfort in these shelters all through the winter, the work was scarcely interrupted. One had, however, to buy wisdom with experience. At first the drift was allowed to accumulate outside against the wall, an error which caused an immense amount of trouble, drift getting in over the top to the serious hindrance of the work. It is absolutely imperative that the outside of such shelters shall be kept vertical, then the bulk of the drift is kept out, as it invariably beats back from a vertical face. As continuance of the work throughout the winter was not expected, the routes to these shelters were not marked out, and frequently they were very difficult to find in the dark ; this occasioned a further considerable loss of time. After the blizzard at the beginning of May, 1902, when the ice was blown out of the Sound and open water came to within 100 yards of the ship, advantage was taken of the circumstance to sink 100 fathoms of line over the edge of the remaining ice, the two ends being secured to the ice 100 yards apart. When the Sound was again frozen over, a suitable hole was cut at each end of this line, then a light trawl (commonly called the D net on account of the shape of its frame), and an additional line was attached, so that the net could be hauled backwards and forwards underneath the ice. This proved an exceedingly profitable investment till one of the ropes broke, then operations were suspended. At intervals, however, cracks occurred in the ice across the mouth of the Harbour, and through some of these the bight of a line was forced for 100 yards; this came to be regarded as the practical working distance. New holes were cut and fresh lines rove, the rest of the work proceeding as before. This operation was not conducted without difficulty or delay from various causes. Another serious impediment to the work of the first winter was the formation of ice crystals on the nets and lines. At the end of May, 1902, two tow-nets were 6 T. V. HODGSON. lowered to a depth of G and 7 fathoms respectively on the same line at No. 3 hole, half a mile from the ship, the total depth of the water being 56 fathoms. Owing to bad weather and the accumulation of drift, these nets could not be recovered for eighteen days. It was then found that the line was thickly covered with thin plate-like crystals of ice, of roughly hexagonal shape, and from one to four square inches in size. The upper net of fine mesh, 150 to the inch, was similarly covered both inside and out ; the lower net of coarse mesh, 50 to the inch, was equally thickly coated, but with crystals of much smaller size, comparatively minute. Naturally the contents of the nets were ruined, their prolonged stay under water would have been sufficient for that, independently of ice crystals. The occurrence of these crystals was at first thought to be due to the prolonged immersion of the nets. However, they occurred constantly from this date, even in twenty-four hours' immersion, but not so badly on the nets. It wras not suspected for some time that depth had anything to do with it, and most of this time I was working alone, and so could not see how far these crystals extended on the lines of the traps. However, on one occasion, Sept. 19, 1902, a trap set in 100 fathoms had been down for three days, and the crystals were measured on the line to a depth of 1 7 fathoms. The line used was a quarter of an inch in diameter ; with the crystals on it, it was increased to something like a foot. Ultimately it was found that under ordinary circumstances, i.e., when nets, etc., could be visited every forty-eight hours at the outside, immersion to a depth of 10 fathoms kept the nets free, the crystals only descending to a depth of 5-8 fathoms. This phenomenon occurred from June to October, when the temperature of the water was 28 "4° F. or — 2° C. By October the temperature of the water had risen to 28 '8° F. and the formation of these crystals diminished, the crystals themselves becoming smaller and more scattered, till at the end of the month they finally ceased to exist. During this month similar crystals formed on the sides of the holes ; they were easily detached, and had to be removed before the nets could be drawn through, in order to prevent their dropping into the net and so spoiling the contents. They disappeared about a fortnight later. By the middle of November the surface temperature of the water went up to 29° F. At the end of December it was 30° F., by the beginning of February it had gone down to 29'5° F, and to 28 '8° F. before the end of the month. The annual range of the sea temperature was, therefore, less than a couple of degrees. Various thermometers were used in these observations, and as some of them were lost it is not possible to apply any correction for error. The tides were irregular, but the ebb and Hood occurred once in the twenty-four hours. After two or three experiments in tide gauges one was finally rigged up on board the ship. It consisted of a sounding wire attached to a heavy weight lowered to the sea bottom, the depth being 9 fathoms. To pass through the ice the wire travelled through a glass tube of narrow diameter, which was filled with paraffin and kept full. Tlic wire then passed over a pulley on board the ship, with another weight at its inner end, and a pointer being attached the rise and fall was indicated on a scale. As the COLLECTING IN ANTARCTIC SEAS. 7 tidal observations are not, for the time being, accessible, I can only say, therefore, that the average rise and fall was about three feet ; the difference between neaps and springs was about a foot. The set of the current through the Sound would naturally be influenced by the tide, but, extraordinary as this may seem, it was not noticed. A current-meter placed two or three hundred yards to the southward of the ship, while working, invariably showed a current travelling to the south-east, or around Cape Armitage. Two holes were constantly kept open in order to obtain specimens, one of these was close to the ship, the other about a mile and a half distant ; others there were, but they were of a more temporary nature. Up to the end of January, 1903, the current invariably carried the lines, that depended from these holes, to the south or south-east according to the position of the particular hole, that is, round Cape Armitage towards the outlet of the Sound between White Island and Cape Mackay. Quite suddenly on Feb. 2, 1903, the current was noticed setting very strongly to the northward, or exactly opposite to the normal direction. This lasted for a few weeks, but it was not constant. It then reverted to the normal and became constant in general direction, but not in strength. I was unfortunately confined to my bunk during the " critical " period of 1904 and was, therefore, unable to note the change of current. If such occurred at that period, no mention was made of it by others ; just before then it had varied considerably in strength but not in direction. As regards the sea bottom, its composition, as far as could be ascertained, was an exact counterpart of the land surface. The heights round Winter Harbour were composed almost exclusively of basaltic rocks, the average elevation of which was over 400 feet, though Crater Hill in the background was 1000 feet high. This extremity of the Ridgway consisted of extinct craters in a more or less shattered condition, the greater part of the rock lying in small angular lumps, with here and there a sprinkling of boulders of very moderate dimensions, and on the lower levels, patches of a fine gravel or coarse sand. The bottom of the Sound was the same wherever it could be examined : angular basaltic stones everywhere, with small patches of volcanic sand, mud and boulders of varying size near the shore. The shoal off Cape Armitage, already alluded to, was more covered with organic debris, chiefly polyzoa and shells ; especially on its south-eastern slopes, which were rather steep. No. 10 Hole was over this slope, a mile and a half S.S.E. from the ship in 125 fathoms. In the north, 10 miles from Hut Point, the Dellbridge Islands rise apparently abruptly from the bottom. The so-called "Glacier Snout" lay a mile nearer the ship, and presented many peculiar features which could not be fully investigated. It is not directly connected with Mount Erebus, and many circumstances point to its being on a submerged ridge, but two soundings taken at the end of our stay only serve to complicate the problem. They were taken against the Glacier Snout, half a mile from its free end ; that on the south side showed bottom at 175 fathoms, that on the north 8 T. V. HODGSON. side 150 fathoms. It is impossible to understand how such a mass of ice, if floating, can hold together at such an angle to the general current. Speaking broadly, it may be said that the Sound forms a deep trench with a fairly even bottom, the greatest depth sounded being close to the permanent or barrier ice some four miles from Cape Armitage ; at that point, 410 fathoms, no bottom was found. The hundred-fathom line lay about a mile from the ship and alxmt half that distance from Cape Armitage. My two principal holes were a mile and a half from Hut Point, in 125 fms., one to the N.W., the other S.E. Two others, quite two miles due west of Hut Point and not far from each other, were in 163 and 178 fms. respectively. Another hole a mile south of the Glacier Snout and eight miles from Hut Point was in 180 fms. Numerous other soundings were taken by Lieut. Barne within a radius of a few miles of Hut Point, but I have not yet seen the details. The ice reaches an average thickness of eight and a half feet in the course of a season, and for operating under such conditions tools of a certain kind are indispensable. After consultation with the engineer, Mr. Skelton, it was decided that all tools should be made of mild steel, case-hardened. The effects of temperature were not always borne in mind, and the muscular A.B. was invariably tempted to use his tools as in temperate climates ; a very slight leverage caused them to snap, so that notwithstanding the skill of the engineering department, there was very soon a shortage of effective instruments. Not being endowed with the average amount of muscular strength, I did not lose my tools in this way. The tools provided consisted of a pick, pointed at both ends, a shovel and a crowbar termed a "pricker." This was of iron, six feet long and about an inch in diameter, with a chisel edge about two inches broad. These tools are essential ; with regard to the pricker, its use for any length of time makes the hands very cold, irrespective of the amount of covering one may wear. The weight of the tool is an important factor, and it should be maintained, though the length of the iron could be reduced to about three feet, and a wooden stock of the same length added. As its only use is as a stabber, the wooden stock would not be a disadvantage. As the ice thickens, and as long as the hole is kept in trim it is only necessary to remove a slab of ice one or two feet thick every day, but as the water is at freezing point for fully six months of the year, the holes freeze up and close in at the sides and bottom ; they therefore have to be shaved in order to maintain their size. A tool was made for this purpose, but the resources of the ship were not equal to making it heavy enough. It should be a sharp chisel about 3 inches wide, and near 10 Ibs. in weight, attached to a wooden handle 9 feet long. Another essential tool, but one readily improvised, is a stout hook at the end of a 12-foot pole. The lines were always carefully placed in the centre of the hole, but were invariably more or less displaced, partly by the current, but more generally by the seals. After the ice had become 4 feet thick the lines were frequently caught up at the lower edge of the hole and fro/en in. This was a frequent COLLECTING IN ANTARCTIC SEAS. 9 source of loss ; but if the ice could lie hooked up from below before any attempt was made to release it, the loss could be avoided. It should be borne iu mind that a large proportion of the work was done in the dark and, apart from this fact, once water gained access to the hole, the whereabouts of the line was more or less a matter of guesswork. Lines cannot be coiled nor wound on a winch ; when frozen they snap only too readily. It was always necessary to " walk away " with them when hauled, and let them lie out straight on the floe. If, however, the depth was greater than 30 fathoms, or thereabouts, they lay out in festoons. Lengths of flexible steel rope not exceeding an eighth of an inch in diameter are strongly recommended, as these can be wound on a small light winch, but it is necessary to be on the sharp look-out for kinks, which are of far greater importance than in temperate climates. The use of steel rope involves the use of snatch-blocks and tripods. A single winch secured to a sledge is sufficient for any number of holes, also a single snatch-block. The tripod should be frozen in over each hole, the rest is a mere matter of management. Another very important tool of which we were quite deficient is an ice saw, some 3 or 4 feet long, with a wooden handle, to be worked by one man. For keeping the holes open and for negotiating cracks these would be invaluable. Our smallest ice saw was 13 feet long, and useless for biological purposes without a number of men. The lines were very frequently " stranded," though never cut through, presumably by the seals corning in contact with them and snapping at them as they passed ; there did not appear to be any other reason for this. The lines had then to be cut through and knotted. Although the line was always hauled over a bar, usually the pricker, it was — especially in the deeper water — deflected by the current and, cutting into the ice, hitched up at every one of the knots, which before long were numerous. This rendered hauling the traps single-handed rather a difficult matter, but the lines stood the strain well ; it was only when completely frozen that they snapped. The traps used were at first wooden frames two feet square at the base, covered with mosquito netting, after the fashion of a lobster-pot. As the ice increased in thickness these rigid traps became difficult to negotiate through the holes, and moreover supplies were not inexhaustible. The ordinary tow- net, tied up at one end and baited, was much more convenient and quite as effective. Swabs attached to the traps were always used and very satisfactory. Dredging in some form was always carried on inside the 25-fathom line, but beyond this depth stationary traps only could be used. However, in deep water (125 fathoms) the trap or D-net was frequently sent down light and very slowly, so as to be carried by the current as much as possible from the vertical. Then one or two 25-lb. sinkers were sent down and the net hauled. Sometimes this was very successful, sometimes it was not. The captures were brought to the ship either in glass bottles or in a large tin-lined packing-case previously made water-tight. In the winter of course everything froze at once and had to be thawed out on board ship. In the summer the specimens were hardly so well off', for, although they did not freeze, 10 T. V. HODGSON. the water was generally full of ice crystals which, with the jolting of the sledge as it travelled shipwarcls, cut the more delicate specimens to pieces. If the flora of McMurdo Sound was poor, the fauna was extremely rich, as the collections described in this and other volumes show. It is to be regretted that the difficulties of the investigation precluded the capture of specimens from greater depths and distances from the ship, so that a more complete comparison of the fauna at different zones could be made. APPENDIX. Two other matters require attention by those who visit the distant south. One concerns the trawls and nets generally. On the outward voyage of the ' Discovery ' it was found extremely difficult, if not impossible, to keep the nets dry owing to constant leakage into the deck-houses. As this bade fair to continue throughout the voyage, as it actually did, all the nets were tarred in New Zealand as an attempt to preserve them ; it was successful in this respect, but it depreciated their value for work in cold temperatures. They became so hard as to be difficult to manipulate, and also inflicted far more injury on the specimens than they would have done if treated in another way. A thorough soaking in oil is suggested. The other matter concerns the work at sea ; as a matter of fact very little was done. An accumulator of some form is almost a necessity, certainly if any extensive work is contemplated. The one provided was the old pattern of india-rubber bands as supplied to H.M.S. ' Challenger.' The instrument was quite useless. The cold weather rendered the rubber bands hard and brittle ; apart from that, the days of the hemp rope are over, and the great weight of steel ropes renders the use of such an accumulator a very cumbrous affair. The only kind that can be used in a Polar climate is one made of steel springs, such as that used by H.S.H. the Prince of Monaco, or by the Norwegian Government on board the ' Michael Bars.' MOLLUSCA. VI.-PTEKOPODA. BY SIR C. ELIOT, K.C.M.G., LL.D. (2 Plates.) THE Pteropods collected by the ' Discovery ' comprise the following species : - Name. Quantity. Locality. 1 . Limacina aiitarctica, Woodward 2. Limacina retroversa * (Fleming) 3. Clio sulca/a (Pfeffer) . 4. Clione antarctica, E. A. Smith 5. SpongMranchaea australis, D'Orb. Numerous Moderately abundant Two specimens and some fragments Numerous Five specimens Winter Quarters, and the region about Lat. 61°, Long. 140° E. From Long. 95° 43' W. to Long. 173° 33' E., and from Lat. 55° to Lat. Gl° S. None from Winter Quarters. Lat. G3° 04' S., Long. 175° 43' S. Winter Quarters. Winter Quarters, and Lat. 55° 31' S., Long. 156° 19' E. Winter Quarters were in Lat. 77° 49' S., Long. 167° 7' 4" E. * Some naturalists might regard the forms here called Limacina retroversa as at least two distinct species. Though L. antarctica and Cl. antarctica are represented by numerous specimens, and clearly are enormously more abundant than the other species, the quantities contained in each tube suggest that they do not occur in such great shoals as the northern forms. I received the specimens in two consignments, described respectively as Pteropods and Pteropods from the Plankton. The former, it would seem, were taken out of holes cut in the ice ; the latter in the open sea. In most of the tubes the Pteropods are mixed up with other forms, such as small crustaceans, larvae of Lamellariidse, and a globular gelatinous mollusc (probably Lamellaria mollis, E. A. Smith). In the majority of specimens the soft parts are well preserved, but the fragile shells are not only broken, but partly dissolved by the fluid in which the animal has been killed or kept. The number of perfect shells in the collection is small. In the above table I have entered Lnnnfuni rer*a is cosmopolitan and bipolar. Is it not probable then that Clione antarctica and Clio nt; limacina, plus some tropical forms of the genus, represent variations of a once cosmopolitan species ? There is nothing unnatural in the idea that such a species may have undergone similar but not identical changes in North and South Polar waters. The species of Clione inhabiting the warmer seas (67. longicaudata, Cl. flavescens, and Cl. punctata) have not been described in great detail, but they do not seem to differ from the Arctic and Antarctic species so profoundly as to forbid the supposition that all may be modifica- tions of one form. It is noticeable that the Arctic and Antarctic species have invariably three pairs of buccal cones, whereas the warm water species have two pairs or only one. The forms of Limacina which predominate in the tropics are not nearly allied to L. antarctica and L. Jn'licina, but Dr. Meisenheimer states that L, ramji " weist ausserordeutlich nahe Beziehungen zu L. helicina auf," * although he separates the two. This species, as to whose independence authors are not agreed, has been found as far north as Lat. 33 S. L. /tcliro/tlex, which is known only by the shell, resembles L. helicina and L. antarctica in having a fiat spire, though it is specifically distinguishable. It is widely, though sparsely, distributed in the warmer waters of the Atlantic. The anatomy of the Pteropods has been so fully described by various authors that in the following notes I have not touched on it, except when necessary for purposes of classification. My best thanks are due to Mr. T. J. Evans, Lecturer on Zoology in the University of Sheffield, for preparing sections and drawings, and for much assistance. LIMACINA. Ten or eleven species have been referred to this genus, but the animals of L. triacantka and L. /u'licoide.y are unknown, and opinions differ as to whether all the other species are really valid. The relationships of L. helicina and L. antarctica, as well as of L. n'troversa, L. lesueuri and L. australis are discussed below. There is some difference of statement as to the presence or absence in this genus of organs called jaws, and possibly some variation in the texture of the * SudpolarExpedition. Pteropodeu, p. 105, 1906. 4 SIR C. ELIOT. organs themselves. Sars, who is quoted by some subsequent authorities, gives (Mollusca Regionis Arcticae Norwegise, 1878, p. 328) maxillae nullae as a character of Fain. Limacinidae, but on Plate XVI., 17, b, he figures a collection of lamellae with denticulate or fringed edges, and explains them (p. 462) as maxilla una 190'" aucta. But in fig. 21, b, of the same Plate, representing the buccal parts of Clione limaciiin, what appears to be one of the hook sacks is described as maxilla una 15""" aucta. It is clear therefore that he did not restrict the meaning of the term maxilla to the ordinary molluscan jaw. Neither in Limacina aatarctica nor in L. retroversa have I been able to isolate any hard jaws, such as are frequently found in Opisthobranchiata, but sections show that the sides of the cavity bear folds which are covered with a very thin chitinous layer. LIMACINA ANTARCTICA, Woodward. See Pelsetieer, 'Challenger1 Reports, Vol. XXIII. (1888), Tliecosmata, p. 22; id., Voyage du S. Y. Belgica, Mollusques (1903), p. 29 ; Meisenheimer, ' Valdivia,' Pteropoden (1905), pp. 7, 8; id., Die Arktischen Pteropoden (1906), pp. 409-413 ; id., Siidpolar Expedition, Pteropoden (1906), pp. 96-98.* The numerous specimens obtained by the Expedition differ considerably in size, colour, and general appearance, and may be classified under three heads : — (A.) Black and yellow specimens. The majority are about 3 mm. wide and 2 mm. or a little less in height, but four are as much as 5 ' 5 mm. broad and rather more than half as much in height. An operculum was often found. The fins, hermaphrodite gland, and the majority of the organs are of a pale lemon yellow, varying considerably in intensity, but contrasting markedly with the black mass composed of the digestive organs, and especially of the liver. The shell is extremely fragile and in bad condition, being not only considerably broken in nearly all specimens, but also pierced by numerous holes. The word picric is written on some of the labels, and probably all these specimens were killed with picric acid. This has caused the fins and head parts to remain well expanded, but the action of the acid has coloured the light portions yellow and partially destroyed the shells. Specimens of this class are recorded from :— (1) Lat, 61° 46' S. } _ Numerous. Long. 140° 12' E. 5 (2) Lat. 61° 40' S. j _ Fairly numerous. Long. 141° 32' E. 5 (;'.) McMurdo Bay . . . . „ „ (4) Lat. 66° 52' S. ) A fuw Long. 178° 15' E. 5 (f>) W. Q. . . . . . „ (6) Wood's Buy . * Full titles and references will be found at the end of the Memoir. PTEROPODA. 5 (B.) Whitish specimens. In these the prevalent coloration is white or grey, the black visceral mass being seen more or less distinctly, according to the transparency of the shell. The animals are not much expanded, the fins being usually retracted, but the shells are better preserved than in the black and yellow specimens, being thicker, more opaque, less broken and less perforated. The breadth is about 3 mm. and the height about I1 75. These specimens were probably put straight into alcohol, which accounts for the contracted state of the soft parts and good preservation of the shell. They are recorded from :— (1) W. Q. ..... Fairly numerous. (2) McMurclo Bay . . . .A few. (C.) These specimens, which are extremely numerous, are distinguished by (a) their small size, the diameter being usually about 1'50 mm., and few whorls; and (b) the position of the fins, which form a sort of hood extending beyond the anterior part of the body. As this hood often bears fragments of shell, the whole animal sometimes bears a resemblance to Limacina inflata, as figured by Souleyet. But a comparison with specimens of that form, kindly lent me by Mr. E. A. Smith, l.s.o., shows that the resemblance is merely superficial, and that there is no true rostrum above the hood. The coloration is varying : pure yellow, black and yellow, white, grey, and dark grey being all found. Some of the animals have been treated with picric acid, and some apparently put straight into alcohol or formol. The majority of the shells are poorly preserved, though in so large a mass of material good specimens were not wanting. An operculum is generally present ; otherwise this form resembles those described above as A and B. and may be regarded as a younger stage. The Expedition brought back twenty-three tubes containing specimens of this type, all captured at Winter Quarters, none being recorded from elsewhere. Taking all the specimens together, I have little doubt that they represent a single species which may be thus described. The shell is between 5 and 6 mm. broad in large individuals, but considerably smaller in the majority, and the height is about half the breadth or rather less. In the best specimens it is white, imperfectly transparent, and faintly but distinctly striated, but the action of the preserving fluid often renders it extremely fragile and the stria tion may disappear. There are 3-6 whorls (5-6 in large specimens) divided by distinct sutures. The last whorl is considerably dilated and terminates in a large rounded lip, which is generally broken. The spire is somewhat flattened. The umbilicus is moderately wide and deep, but is not surrounded by any raised keel or special border. In large specimens the fins (fig. ib) are about 4 mm. long and 3 mm. broad across the tips. They are shaped much as in L. lu'lici/ia and bear a small accessory lobe. The right tentacle is well developed, the left rudimentary. The foot is ample 6 SIR C. ELIOT. and the posterior lobe is rather deeply divided. An operculum is often present in specimens of both small and moderate size, certainly in several which have a diameter of at least 3 mm., but is absent in the largest and is probably caducous in adult life. It is much as figured by Pelseneer (' Belgica,' figs. 70, 71) and has a short sinistral spire of two whorls (fig. 2). The balancer or long narrow lobe on the right side of the mantle is well developed. The jaws mentioned by some writers could not be found by ordinary dissection, but in transverse sections there were seen in the part of the buccal tube lying in front of the radula, dark pigmented folds covered by a very thin layer of a lighter colour and apparently chitinous. In the floor of the cavity are two ciliated grooves (fig. 3). In individuals having a diameter of 3 mm. or more the radula consists of 8-11 rows containing three teeth each. The teeth (fig. 4) present slight but distinct and persistent differences from those of L. helicina (fig. 5) and are larger in proportion to the size of the animal. In the median teeth (4a) the hair-like denticulation is longer and extends higher up the sides of the median cusp, which consequently appears to be shorter ; the base is straighter and bears at either end two or more lobes and bulges. The laterals (4b) are less curved than in L. hdicina and the denticulation, as in the median cusp, extends higher. In the oldest row of teeth the laterals are very thin (4c) and the base of the median tooth is simpler, without bulges. The whole interior of the stomach (fig. 6) is lined with a thin layer of chitin which gives rise to five stomach plates and also to various prominences and spines (Ga) which are larger in the cardiac portion, but do not form four definite accessory plates, such as some authors have reported in L. hdicina. The four large stomach plates (fig. Ga) consist of a rectangular or oval base out of which rise one or more prominences with strongly jagged edges. These plates appear to play on one another, which probably modifies the details of the shape in each case : in two the point of the projection is more acute and more bent than in the others. When the four pro- jections are in contact a conical hollow remains between them posteriorly and into this fit the prominences of the fifth plate (fig. 6a, e), which is smaller than the others and lies below them on the pyloric wall of the stomach, but is of essentially the same form, though generally seen sideways and hence apparently more triangular. In all the specimens examined the stomach was found to contain globigerina and diatoms. The inner whorls of the shell are entirely filled with the white hermaphrodite gland. Authorities are not agreed whether this form is a separate species (Pelseneer) or a variety of L. hdicina (Meiseuheimer). In the hope of contributing to a decision, I have compared with the ' Discovery ' collection a large number of specimens kindly furnished me by Professor D'Arcy Thompson, C.B. (from Davis PTEROPODA. Straits and North Pacific), the British Museum and others. The following table will show the points of difference which I have found to be constant :— LlJIACINA ANTARCTICA. 1. Maximum breadth observed 5' 5 mill.; fins about 4 mill. long. 2. Shell with very fine transverse striation or with none at all. (But see what is said above as to the injuries sustained by the shells.) 3. Umbilicus without any sort of keel or distinct border, even in the largest specimens. 4. The colour of the animal is light, with the exception of a distinct dark mass composed of the viscera and situated chiefly in the second half of the first whorl. The inner and upper whorls are entirely light (fig. Ib). 5. The posterior lobe of the foot is more deeply and distinctly divided than in L. 6. The hair-like denticulation of the teeth extends to a considerable height, so that the main cusp is less conspicuous. The base of the central tooth is fairly straight, with knobs at the end. LlMACINA HELICINA. 1. Considerably larger. Maximum breadth observed 0 mill. ; fins 10 mill. long. i'. Striatiou much stronger and more distinct : sometimes darker than rest of shell. 3. Umbilicus surrounded by a very distinct circular raised border, which is invariably present in well-preserved specimens of moderate size. 4. The upper and inner whorls are marked with a dark stripe following the direction of the spiral, so that the shell when seen from above presents an alternation of dark and light spiral stripes. The dark stripe is not hepatic, but is formed by a pigmented membrane which appears to be continuous with the mantle (fig. IA). 5. (i. The denticulation is less developed and the cusp consequently seems more prominent. The base of the central tooth is hollowed out almost into a horseshoe shape. Other points, such as the shape of the operculum mentioned by Prof. Pelseneer, seem to me less certain. Whether the differences tabulated above are sufficient specific characteristics must depend on each naturalist's view of what constitutes a species, there being no accepted definition of specific difference. But as far as the collections which I have examined are concerned, these differences are persistent and concomitant, and it seems to me that when so decided a character as the presence or absence of the raised border round the umbilicus is accompanied by differences in size, colour and the teeth of the radula, the two forms are entitled to specific rank, though the divergences by no means show that they have originated independently, but rather support the idea that they are differentiations of a common ancestor or one of the other. VOL. III. SIR C. ELIOT. LIMACINA RETROVERSA, Fleming. See especially Meisenheimer on Limacina retroversa, Siidpolar Expedition (1906), IX. Band, Zool. I. Band, Heft II., pp. 103-105 ; Eydoux and Souleyet on Spirialis australis, Revue Zool. (1840), p. 237, and Bonite (1852), p. 222 ; Pelseneer, ' Challenger ' Report, LXV., pp. 25-27 ; Munthe, Pteropoder, pp. 8, 9 (1887). There are six tubes containing specimens of a whitish Limacina of small or moderate size, with a spire of somewhat varying height, but never so low as that of L. ht'lie'iiHi or L. antarctica. The labels are :— 1. Lat. 55° 44' S. Long. 95° 43' 30" W. 5 fathoms (11 spec.). 2. Lat. 56° 12' 45" S. Long. 136° 18' 30" W. 10 fathoms (3 spec.). 3. Lat. 57° 25' S. Long. 151° f E. (Several spec.) 4. Lat. 59° 19' S. Long. 120° 24' 30" W. 5 ms. (6 spec.). 5. Lat. 59° 34' S. Long. 106° 28' 13" W. 5 fathoms (4 spec.). 6. Lat. 61° 13' 30" S. Long. 173° 33' E. (Several spec.) The tubes contain comparatively few specimens, and suggest that this species is not found in abundant shoals. The shells show considerable variation in form (fig. 7). No differences were found in the animals, though, as they were without exception retracted into their shells, the investigation of the foot and fins was difficult. An accessory lobe was, however, found on all the fins which could be extended, and after examining numerous specimens of L. retroversa from the coast of Scotland, I can confirm Meisenheimer's statement (Siidpolar Exped., p. 104) that the lobe occurs in this northern form. The radula appears to be much the same in all specimens, and substantially as in L. rt'truwrm. The shell varies in colour from greyish white to yellowish brown, but is always rather opaque, not striated, but covered with fine granulations arranged in no apparent order. The height of the spire varies from 1 mill, to 2 mill., the latter dimensions being rare, and the maximum breadth across the last whorl is 1 mill. The umbilicus does not vary materially in shape ; it is distinct, straight, rather narrow, and I did not find the distinction in breadth mentioned by Prof. Pelseneer ('Challenger' Reports LXV., pp. 26 and 27). The mouth is subquadrangular. The variation in the shape of the shell produces two types. Type A (fig. 7A) is tall, with very deep sutures and six or seven whorls, which increase symmetrically in size, the last not being disproportionately large. In many of these shells, as preserved, the columella is not continued at the side of the mouth. Type B (fig. 7c) is smaller and lower ; the sutures are not so deep ; there are only four or five whorls, and the last whorl is disproportionately large and swollen, PTEROPODA. 9 If these forms were sharply distinguished from one another, they might lie regarded as separate species, but in a few cases intermediate variations (fig. 7s) occur, such as a tall shell with deep sutures and seven whorls, of which the last is disproportionately larger than the others. Moreover, all the variations may be found in the same tube, which seems to show that they live together in their natural state. I think that the low form in L. lesueuri, and some varieties of the high form, seem to be typical examples of L. au*tmlii*. But if these forms pass into one another, and are not specifically distinguishable, they are not, in my opinion, specifically distinguishable from L. rctroversa. Dr. Meisenheimer (Siidpolar Exped., p. 103) has already identified L. australis with this northern form. I have compared the contents of these six tubes with very numerous specimens of L. rt'troversa captured in the North Sea (where it seems to occur in vast quantities) and kindly lent me for examination by Prof. D'Arcy Thompson, C.B. The only points in which the whole series of Antarctic specimens can be said to differ from the northern specimens are the colour and surface of the shell. In the Antarctic forms it is opaque, not striated, and covered with a fine, irregular granulation ; in the northern form it is hyaline, transparent, and finely striated, the stride being composed of dots arranged in fairly regular, but not perfectly continuous, lines. These differences do not appear to me to have specific value. I can find no distinction in the breadth of the umbilicus or the obtuseness of the spire. Though L. rctroversa is commonly said to have an acute spire, many of my specimens are quite as blunt at the tip as L. australis. Meisenheimer (Siidpolar Exped. p. 106) regards L. rangi and L. Ifx/d'/tri as separate species. I confess I doubt whether this distinction will be found to hold good, but the specimens now under consideration are certainly not L. raugi as defined by him, for the spire is higher, an accessory lobe is present on the fin, and the umbilicus is not particularly broad. CLIO SULCATA, Pfeffer. Pfeffcr, Uebersicht der auf S. M. Schiff Gazelle gcsammelten Pterpoden, Monatsb. k. preuss. Akad. AViss., Berlin 1870, p. 240. Pelseneer, ' Challenger ' Reports, No. LXV., Thecosomafca, p. G2. Two specimens labelled " 1. 1. '02. 63° 04' S., 175° 43' E.", of nearly the same size and measuring about 18 '5 mm. in length and 11 '5 mm. in breadth. The shells are very fragile and both are broken, but they must have been about 14 '5 mm. long and 8 mm. broad at the top. When the animal is inside they are coloured rosy red by the viscera, but when empty are of a bluish white. The sides are inclined towards one another, and are not parallel in any part. There are lateral keels on the anterior portion of the shell, but they disappear before the D 2 10 SIR C. ELIOT. end. The shape of the lips is doubtful, owing to the injuries that they have sustained. The anterior portion of the back seems to have been triangular. The ventral surface is not re-entrant, but flattish and only slightly convex. The dorsal surface is moderately convex. The anterior part is broken, but appears to have borne a median ridge and four lateral ridges, which disappear in the posterior half. The whole surface of the shell bears numerous fine transverse ridges. After the termination of the animal inside, the shell is produced into a thin point 4 mm. long. The embryonic shell resembles Pelseneer's figure (I. c., pi. II., 9) of Clio sulcata rather than Clio australis. The foot, wings and other portions of the animal protruded from the shell are yellow, the viscera reddish. The wings are ample, about 6 mm. long and 5 mm. wide, deeply bi-lobed and with wavy edges. The interior of the liver is deep red. The stomach contains four large plates, bearing a conspicuous Y-shaped ridge on the outside. There also appears to be a fifth plate, smaller, indistinct and triangular, as well as a double row of minute plates. The radula is tri-seriate. The sides of the teeth are somewhat irregular and indented, but not serrulated. I think that these specimens belong to the Clio sulcata of Pelseneer, /. c., but feel some doubt whether that species is really identical with Pfeffer's Cleodora sulcata. To the same species are probably referable a small Clio, to which fragments of shell are attached and two posterior ends of shells, one of which bears remarkably large and distinct transverse furrows. They are all labelled 27. 12. '01. 54° 01|' S. 170° 49' E. CLIONE ANTARCTICA, E. A. Smith. See E. A. Smith, Coll. 'Southern Cross' Mollnsca (1902), p. 210, and pi. xxv., figs. 7, 8. See also Meisenheimcr on Glione limacina, var. antarctica, in Siidpolar Expedition, Pteropoden (lOofi), pp. 101-103. The labels state that the numerous specimens representing this form were all captured at Winter Quarters in from three to ten fathoms, the great majority at the latter depth. They fall into two classes, chiefly distinguished by their colour, some being yellowish and generally well expanded ; others, brownish or greenish grey, and much more contracted. These differences seem due to the method of preservation rather than to natural variations, and the labels make it probable that the yellowish specimens were killed with picric acid. The measurements of a large specimen are : length, 17 mm., breadth of the body at its thickest part, G mm., breadth across the fins, 9 mm. The colour is usually a pale lemon yellow (probably representing an original white), sprinkled with round dots of opaque yellow. The number of dots varies greatly, but they are entirely absent in comparatively few individuals. They are much more PTEROPODA. 11 conspicuous in the yellow than in the grey specimens. In their natural condition the integuments seem to be semi-transparent, especially above the foot, where the burral muscles are often clearly visible. Below the foot they are more opaque, but the blackish viscera can be somewhat indistinctly discerned. The shape is moderately stout and moderately elongate, either tapering fairly symmetrically to the terminal knob, or prolonged into a distinct tail. The majority of the specimens have preserved the three larval rings, and when they are absent it seems probable that they have been obliterated. The first ring is represented by a circular baud a little below the mouth, bearing 14-18 whitish prominences set at regular intervals. Some distance below the fins and about the middle of the body is the second ring, a very distinct line often accompanied by a deep constriction At the end of the body is found, with a few exceptions, another deep constriction dividing the tip from the rest, so that the animal terminates in a knob, which, in well- preserved specimens, is surmounted by a circular frill. The fins are of moderate size, transparent, and show inside a network of muscles. They are of somewhat varying but rounded outline, and are never triangular or quadrilateral. In many cases the base is much narrower than the rest, and this feature is probably natural. The two anterior lobes of the foot are fairly ample and inclined so as to form an acute angle. They are attached to the body only by a narrow base, the greater part of the flap being entirely free. The posterior lobe is an acute-angled triangle, rather long and thin, but proportionately to the size of the animal larger and stouter than in Cl/'oue l/mncina. In specimens in which the buccal parts are fully everted there may be seen two pairs of tentacles, three pairs of buccal cones, and a pair of hooksacks. The anterior tentacles are distinct and fairly large. The posterior tentacles are small, and in most specimens can only be found by following the nerves, having become invisible owing to retraction. The buccal cones are soft in the best preserved specimens, but very distinct. The middle one on either side is the largest. The two which are nearest to the foot are set close together, but are separated from the dorsal cone by a somewhat larger interval (fig. lla). The hook sacks, which are not uufrequently everted in the form of two bundles, contain 60-70 yellowish hooks, slightly curved and somewhat hollowed out on the inner side. They are set in several rows, those at the end being smaller than the rest and forming a bundle. There are no jaws. The radula (fig. 10) consists of about thirty rows, which have a maximum formula of 8. 1. 8, but the median tooth is very small, and is only found in one or two of the hindmost rows. Except in this posterior portion, the radula is split into two halves, which extend over two protuberances towards the right and left, so that the whole organ has somewhat the shape of the letter Y, and in the greater part of its length offers no place for a median tooth. This disposition was constant in all the radulte examined, and seems to be natural and not due to 12 SIR C. ELIOT. distortion. The following is an analysis of a raclula of 32 rows, row No. i. being the hindmost :— Eows i-ii . 818, the median tooth being smaller in i than in ii. Rows iii-ix . 808. Row x 7r 0 r7, where r indicates a rudimentary lateral.1 Rows xi-xiv . 707. Row xx . . Gr 0 r6 ,, ,, ,, ,, Rows xxi-xxvi. 606. Rows xxvii-xxx 505. Row xxxi . 404. Row xxxii . 303. The shape of the teeth is much as in Ciione limacina, except that the median teeth (llgh) are markedly smaller and less distinctly cuspid, and that the laterals in the hindmost rows (lief) have forked bases. It is noticeable that several specimens have been preserved in the act of holding and apparently eating small elongate fishes, which are still attached to them (fig. 12). In Cl. limacina the penis is large, frequently found exserted, and provided with a large accessory organ (vide Boas's figure reproduced by Meisenheimer in Die Arktischen Pteropoden, p. 415) ; but these characters are not found in any of the present specimens of Cl. antarctica. The penis is small, invariably retracted, and no accessory organs were discovered. Too much stress should not be laid on this difference, for no doubt the accessory organs may have a very different appearance in the same species when exserted and when retracted. The presence of the larval rings and the small size of the penis naturally suggest that this form is immature, and it is also noticeable that the specimens were all captured between the months of November and March (though in different years), most of them in January and February. This certainly makes it probable that they are all in the same and possibly not adult stage of development. On the other hand, it is clear from a comparison of Arctic and Antarctic specimens of the same size that the young Ciione limacina is not more like Cl. antarctica than are the full-grown individuals. Also the type specimens of Clime antarctica, captured by the ' Southern Cross ' off Cape Adare and lent to me for examination by the kindness of Mr. E. A. Smith, i.s.o., resemble those found by the ' Discovery ' in most external points except the colour, which is dirty green with purplish spots, a difference no doubt due to the method of preservation. The length is 20 mm. or a little less, the larval rings are more or less distinctly visible, the fins, foot, and buccal cones are as in my specimens. • 1 The conformation of the raclula may be due to one or both of two causes : — (a) In most opisthobranchs the front, that is the earliest rows of the raclula, contain fewer teeth than the posterior or later rows. (6) As, in this case, the radula is split into two portions, it is possible that not only the central tooth, but the inner laterals on either side are worn away, in which case r would indicate a vestigial tooth. PTEROPODA. 13 These specimens found by the ' Discovery ' seem referable to Cl. (iiitarctica, E. A. Smith (/. c.). They can hardly be identified with Cl. longicaudata, Cl. flavewnx or Cl. punctata, because those species, though imperfectly known, are said to have only one or two, and not three pairs of buccal cones. In my opinion they are also specifically distinguishable from Clioue Umncimi, though the species are, no doubt, nearly allied. The superficial difference in appearance is striking, and the divergent characters of the two species may be tabulated as follows :— CLIONE ANTARCTICA. 1. The part of the body behind the fins is shorter than in the Arctic form. A specimen 18 mm. long consists of G mm. head and fins + 12 rnm. body. There is a distinct neck behind the fins. 2. Considerably smaller than the Arctic form. Few individuals exceed 20 mm., even when arti- ficially extended. E. A. Smith gives 22 mm. as the length ; presumably the maximum of his specimens. 3. The integuments are thicker, firmer, and less transparent than in the Arctic form. In most specimens they are plentifully be- sprinkled with opaque yellow spots, some- times a little raised. 4. Three, or at least two, larval rings are habitually present in individuals measuring 15 mm. or more in length. 5. The base of attachment for the anterior lobes of the foot is a narrow band. The posterior lobe is larger and stouter in proportion to the anterior lobes than it is in Clione limacina. G. There is an interval between the dorsal cone and the other two. The median cone is the largest. 7. Median tooth very small, and present only in hindmost rows of radula. Laterals in hind- most rows have forked bases. The number of laterals gradually increases from 3 to 8, the innermost teeth of the half row being sometimes rudimentary. 8. Penis small, and presence of accessory organ doubtful, though not disproved. 0. The visceral mass extends backwards almost into the posterior third of the body. CLIONE LIMACINA. 1. A specimen 18 mm. long consists of 2'5 mm. head and fins + 15 -5 body. The broadest part of the body is just behind the fins, and as far as there is a neck it is between or above the fins. 2. Specimens -40-45 mm. in length are frequent. 3. The integuments are thin and transparent. Though spots are present they are not con- spicuous, and as a rule can only be seen when carefully sought for. The whole animal is flabby, and almost gelatinous. 4. No larval rings found in individuals measuring as much as 10 mm. When traces of the posterior ring are found in small specimens it is not shaped as in Clione antarctica. 5. The base of attachment for the anterior lobes is broad. G. The cones are equidistant. The dorsal is the largest and the ventral smallest. 7. Median tooth larger, and present in all or most rows. Laterals with forked bases not found. The number of laterals does not increase so markedly, and the rudimentary teeth are found at the outer ends of the rows. 8. Penis proportionately much larger, and provided with a large accessory organ. !). The visceral ma?s is more compact .and rounded, extending only a little way behind the fins. 14 SIR C. ELIOT SPONGIOBRANCHAEA AUSTRALIS, D'Orb. Sue especially Pelseneer, 'Challenger' Report LVIIL, pp. 18-20 ; Meisenheituer, ' Valdivia,' pp. 47-49 ; ill., Siidpolar Expetl., pp. 99-101. One specimen labelled "Winter Quarters, 19. 11. '03. Mosquito net, 10 fathoms." Four others labelled "21. 11. '01. Lat. 55° 31' S., Long. 156° 19' E. ; 15 fathoms." These localities support the idea that the species is circumpolar. A large elongated specimen is about 30 mm. long and 8 mm. broad, another of about the same volume is contracted and stouter, measuring 22 mm. in length and 1 1 in breadth. The colour of the body is violet, grey or brown, with ill-defined bauds of lighter colour round the median constriction and the posterior gill. The buccal parts and the appendages which bear the suckers are yellowish white, and contrast strongly with the body colour. The foot is bluish with yellow edges, the fins yellowish. The lateral gill is hardly visible in any of the specimens. It is at most an inconspicuous bladder-like projection which interrupts the median constriction, and is lighter than the surrounding parts. The posterior gill is distinct and well-developed. The median lobe of the foot is long and tapering, the side lobes are small, and the space between them bears a fewr deep furrows. The parts behind the head, including the fins, are much contracted, but in the only specimen where the fins can be seen they appear to be about G mm. long, and broader, and more deeply lobed than previous authors have described. The buccal parts are everted in one specimen. The large proboscis bears a papilla as described by Pelseneer, and at its base are two large and distinct tentacular flaps. Each of the acetabuliferous appendages bears 8 stalked suckers, which increase in size upwards. The two lowest are very small ; the upper ones are about 1 mm. wide. Just before the radula is the jaw, which appears to be a collection of small straight spines or teeth. At the sides of the radula are two small short hook-sacks, filled with hooks of various shapes. The formula of the radula is about 26 x 8. 1. 8, and the teeth are as in Pelseneer's plates. The median tooth is tricuspid. The laterals are longish, slender, and curved at the tips. The first lateral bears a denticle on the inner side of the base which is not found in the others. Winter Quarters appears to be the furthest southern record of Sp. australis, which is probably circumpolar, since it is now recorded from Long. 60° W., and Long. 5° E. to Long. 30° E , Long. 54° E. and Long. 167° E. It is recorded from as far north as Lat. 35° S. PTEROPODA. 15 MEMOIRS REFERRED TO ABOVE. 1. BOAS. — Spolia atlantica, Videnk. Selsk. Ski1., 6to Raekke, naturvid. og math. Afd. 4, Bd. 1. Kjobenhavn, 1886. 2. EYDOUX ET SOULEYET. — Description sornruaire de plusieurs Pteropodes nouveaux ou imparfaitement connus. Revue Zoologique, 1840. 3. IID. Voyage autour du monde, execute pendant les annees 1836 et 1837 sur la corvette ' Bouite.' Zoologie, tome II. Paris, 1852. 4. MEISENHEIMER. Pteropoda : in the Wissenschaftliche Ergebnisse der Deutschen Tiefsee Expedition auf dem Dampfer Yaldivia, 1S98-1899. Jena, 1905. 5. ID. Die arktischen Pteropoden : in Fauna Arctica. Jena, 190(i. 6. ID. Die Pteropoden : in Deutsche Siid-Polar Expedition, 1901-1903. ix. Band, Zoologie i. Band. Heft ii. Berlin, 1906. 7. ID. Die tiergeographischen Regionen des Pelagials, auf Grund der Verbreitung der Pteropoden. Zoolog. Anzeiger xxix. (1905), pp. 155-163. 8. MUNTHE. — Pteropoder i Upsala Universitets Zoologiska Museum. Bihang till K. Svenska Vet. Akad. Handlingar, Band 13, Afd. iv. no. 2. Stockholm, 1887. 9. PELSENEER. — Challenger Reports, vol. xix., 1887. Gymnosomata. 10. ID. op. dt., vol. xxiii., 1888. Thecosomata. 11. ID. op. cif., vol. xxiii., 1888. Anatomy. 12. ID. Mollusques : in Resultats du Voyage du S. Y. Belgica. Anvers, 1903. 13. G. PFEFFER. — Uebersicht der wiihrend der Reise um die Erde in den Jahren, 1874-187C auf S. M. Schiff Gazelle und von Herr Dr. Jagor auf seiner Reise nach den Philippine!! in den Jahren 1857- 1861 gesammelten Pteropoden. Monatsbericht der K. Akademie der Wiss. zu Berlin 1879. pp. 230-247. 14. G. 0. SABS. — Bidrag til kundskaben om Norges Arktiske Fauna. I. Mollusca regionis Articae Norvegiae. Christiania, 1878. DESCRIPTION OF FIGURES IN PLATES I. AND II. 1. Distribution of colour in animal of Limacina helicina (a) and L. antarctica (b), the shell being removed. 2. Limacina antarctica : operculum. 3. Transverse section through buccal cavity of Limacina antarctica : (aa) folds covered with thin chitinous layer ; (b) radula ; (c) ciliated groove. 4. Limacina antarctica : teeth. 4a median ; 4b-e lateral teeth. 5. Limacina helicina : teeth. 5a median ; 5b lateral teeth. 6. Limacina antarrfira : section through stomach. 1-4 stomacli plates ; (a) chitinous spines. 6a. Limacina antarctica : stomach plates detached. 7. Limacina retroversa : three varieties. 8. Clione antarctica. 9. Clione anttirctica .- anterior end of a specimen in which the buccal parts are everted so as to show the hook sacks. Only two of the three pairs of buccal cones are visible. 1 0. Clione antarctica : radula. 11. Clione antarctica: separate teeth, (a-d) laterals; (e-f) laterals from the hindmost rows; (ir-h) median teeth. 1 la. Clione antarctica: side view showing buccal cones. 12. Clione antarctica : specimen captured in the act of eating a small fish. VOL. III. E Antarctic (' Discovery ') Exp. PLATE I. a. T. J. E. del.] Limacina antarctiea and L. helicina. ^Buttei'worth se. Antarctic (' Discovery') Exp. a.. PLATE II. c. 12 T. .). E. del.] Clione antarctiea. [Butterwortli so. CEUSTACEA. III.-AMPHIPODA. BY A. 0. WALKER, F.L.S. (13 Plates.) THE collection of Arnphipoda consists of fifty-three species, of which eighteen are new to science, belonging to forty-three genera, of which four are new. This may not appear a very large number considering the length of time the ' Discovery ' was in the Antarctic Seas, yet as (with the exception of the pelagic Hyperiids taken on the voyage) all but some nine species were collected from holes in the ice at the Winter Quarters, and, therefore, from a very limited area, it appears to me to reflect great credit on the energy and persever- ance of Mr. Hodgson under unusual climatic conditions. The long sojourn of the ' Discovery ' in one spot enables us to observe the seasons at which different species visit shallow water, generally for the purpose of depositing their ova or young. In the case of the most abundant species, Orchomenopsis rossi, A. 0. W., of which Mr. Hodgson says that " It was quite the usual thing to take ten to thirty thousand at a haul," I only observed one male with fully developed lower antennae and no females with ova, though some measured as much as 25mm. The young had probably been born at a considerable depth, and had a-t once made their way to comparatively shallow water, the parents remaining in deep water. Again, the almost equally abundant Eusirus propinquus (G. 0. Sars) only exceeded 25mm. in four specimens, three females with ova or young measuring 48mm., and one male measuring 50mm. This species resembles in this respect Gammardlus \Amathilla\ homari (Fabr. ), which I have observed to visit the north coast of Wales in the early spring, when alone the large adult females, and more rarely males, measuring nearly lin. in length, can be taken between tide-marks ; in the summer months every tidal pool swarms with young specimens. As in the Arctic Amphipoda, the Lysianassidse greatly preponderate in the number of genera, species, and individuals. The typical Gammaridse, as restricted by Mr. Stebbing in establishing the families Melphidippidae and Lilljeborgidaj, are unrepre- sented. In Professor G. 0. Sars' Amphipoda of Norway there are nine genera with twenty-one species ; and in Professor Herdman's Ceylon collection seven genera with fifteen species. Among the Gammaridae several species are remarkable for their wide distribution : Ampelisca macrocephala (Lilljeborg) is an abundant Arctic species, though found also in E 2 A. 0. WALKER. temperate seas ; Eusirus propinquus (G. 0. Sars) and Melphidippa macrura (G. 0. Sars) have only been recorded before from the more northern waters of Norway ; Leucothoe spinicarpa (Abildgaard) appears to be ubiquitous, and I am unable to see any difference between those taken from the ice-holes of the Winter Quarters and those from our own seas and the tropical seas of Ceylon and the Maldives. This is an ascidiicolous species, and probably owes its wide distribution to the drifting of its host by currents and winds. The same may be said of the two spongicolous species, Polycheria antarctica (Stebbing) and Colomastix pusilla (Grube), of which the former has also been taken in Ceylon, but not further north ; while the latter has been found in the British Isles, the Mediterranean, and Ceylon, but is not recorded from Norway or Arctic seas. These species must have a great capacity of adaptation to extremes of heat and cold. On the other hand, Orchomenopsis rossi appears to be able to exist only in water just above the freezing point.* As species remarkable for peculiarity of structure may be mentioned the following : Hyperiopsis australis, of anomalous structure, and belonging to a genus so rare that previous to the capture of the single specimen in this collection only two individuals of another, but nearly allied species, H. Voeringii G. 0. Sars, had been taken off the coast of Norway ; Thaumatelson herdmani is the only known Amphipod which has its telson set on in a vertical plane ; in the rest of the Stenothoidse it is horizontal and generally spoon-shaped, with the concave side uppermost. Epimeria macrodonta is characterised by the long curved and sharp teeth on the body segments ; while Ipliimedia hodgsoni has these so densely clothed with fine spines directed backwards as to have a shaggy appearance. All the four species of Ipliimedia in the collection are of very large size compared to the northern species, measuring from 20 to 45mm. in length. Lastly, the remarkable development of the meral joints of the last three pairs of perseopods in the adult males of Seba antarctica, may be mentioned. CLASSIFIED LIST OF 'DISCOVERY' AMPHIPODA. HYPERIIDEA.f FAM. VIBILIID^:, GLAUS. GENUS VIBILIA, H. Milne Edwards. V. projiinqua, Stebbing. FAM. CYLLOPID^B, BOVALLIUS. GENUS CYLLOPUS, Dana. G. magellanicus, Dana. FAM. HYPERIID^E, DANA. GENUS HYPEEIA, Latreille. H. ijaitidichaudi, Milne Edwards. H. macronyx, A. 0. Walker (1906). * ' Southern Cross ' Paper, Journ. Linn. Soe., XXIX., p. 45 (1903). t For references to and descriptions of the Hyperiidea, see " Bovallius, Monograph of the Amphipoda Hyperiidea " (Kongl. Svenska Vetenskaps-Akademiens Handlingar, Band 21 and 22, 1887 and 1889). AMPHIPODA. GENUS HYPEROCHE, Bovallius. H. lutkcnides, A. 0. Walker (1906). GENUS HYPERIELLA, Bovallius. H. dilatata, Stebbing. GENUS EUTHEMISTO, Bovallius. E. ijaudic-haudi, Guerin. FAM. ANCHYLOMEKID^, BOVALLIUS. GENUS EUPRIMNO, Bovallius. E. maci-opa, Guerin. GAMMAEIDEA. ^1 FAM. HYPERIOPSID^, BOVALLIUS. GENUS HYPERIOPSIS, G. 0. Sars. H. anstralis, A. 0. Walker (1906). FAM. LYSIANASSIMJ, G. 0. SARS. GENUS CIIEIRIMEDON, Stebbing. C.fowjneri, A. 0. Walker. 0. hansoni, A. 0. Walker. GENUS WALDECKIA, Chevreux (1900). W. obesa, Chevreux, Expn. Antarctique Fran$aise, p. 13. GENUS ARISTIAS, Boeck. A. antarcticm, A. 0. Walker (1906). GENUS ORCHOMENE, Boeck. 0. goniops, A. 0. Walker (1906). GENUS ORCKOMENELLA, G. 0. Sars. 0. pinguides, A. 0. Walker. 0. fran 1:1 in I, A. 0. Walker. 0. chelipes, A. 0. Walker (1906). GENUS ORCHOJIENOPSIS, G. 0. Sars. 0. rosxi, A. 0. Walker. GENUS TRYPHOSA, Boeck. T. ntnri'fii/i, A. 0. Walker. T. Icergueleni, Miers. GENUS URISTES, Dana. U. giyas, Buna. GENUS PODOPRIONIDES, A. 0. WALKER (1006). P. incerta, A. 0. Walker (1906). FAM. IMIOXOCKI'IIALID.E, G. <>. SABS. GENUS HAHPINIA, Boeck. H. obtusij'rnns, Stebbing. 4 A. 0. WALKER. FAM. AMPELISCID^E, G. 0. SARS. GENUS AMPELISCA, Kroyer. A. macrocephala, Lilljeborg. FAM. STEGOCEPHALID.E, G. 0. SARS. GENUS EUANDANIA, Stebbing. E. gigantea, Stebbing. FAM. LETJCOTHOID^E, G. 0. SARS. GENUS LEUCOTHOE, Leach. L. spinicarpa, Abildgaard. FAM. STENOTHOID^l, G. 0. SARS. GENUS PROBOLOIDES, Delia Valle. P. antarcticus, A. 0. Walker (1006). GENUS PEOBOLIELLA, A. 0. Walker (1906). P. typica, A. 0. Walker (1006). GENUS THAUMATELSON, A. 0. Walker (1906). T. herdmani, A. 0. Walker (1906). FAM. OEDICERIOE, G. 0. SARS. GENUS OEDICEROIDES, Stebbing. Oe. newnesi, A. 0. Walker. Oe. calmani, A. 0. Walker (1906). FAM. EPIMERIID.E, G. 0. SARS. GENUS EPIMERIA, Costa. E. inermis, A. 0. Walker. E. macrodonta, A. 0. Walker (1906). GENUS EPIMERIELLA, A. 0. Walker (1906). E. macronyx, A. 0. Walker (1906). FAM. IPHLMEDIID^E, STEBBINQ. GENUS IPHIMEDIA, Rathke. 7. pacifica, Stebbing. /. echinata, A. 0. Walker (1906). 7. lonffipes, A. 0. Walker (1906). 7. hodgsoni, A. 0. Walker (1906). FAM. EUSIRID^), G. 0. SARS (1895). GENUS EUSIRUS, Kroyer. E. propi/iqtti/s, G. 0. Sars. E. microps, A. 0. Walker (1906). FAM. CALLIOPIID^E, G. 0. SARS (1895). GENUS ORADOREA, A, 0. Walker. 0. longimana, A. 0. Walker. GENUS ATTLOIDES, Stebbing. A. serraticauda, Stebbing. GENUS STEBBING r A, Pfeffer. 8. gregaria, Pfeffer. AMPHIPODA. 5 GENUS PONTOGENEIA, Boeck. P. magellanica, Stebbing. FAM. ATYLID^E, G. 0. SARS (1895). GENUS ATYLUS, Leach. A. walkeri, Stebbing (1900). FAM. DEXAMINID^, STEBBING. GENUS POLYCHERIA, Haswell. P. antarctica, Stebbing. FAM. MELPHIDIPPID^, STEBBING. GENUS MELPHIDIPPA, Boeck. M. macrura, G. 0. Sars. FAM. LILLJEBORGIID^;, STEBBING. GENUS LILLJEBORGIA, Sp. Bate. L. dulia, Haswell. FAM. PHOTID^E, G. 0. SARS (part). GENUS HAPLOCHEIRA, Haswell. H. barlimana, G. M. Thomson. GENUS EURYSTHEUS, Bate. E. longicornis, A. 0. Walker (190G). FAM. SEBID.E, A. 0. WALKER (190G). GENUS SEBA, Stebbing. Seba antarctica, A. 0. Walker (1906). FAM. ISCHYROCERID^l, STEBBINQ. GENUS HEMIJASSA, n. H. goniamera, A. 0. Walker. FAM. COLOMASTIGID^, STEBBING. GENUS COLOMASTIX, Grube. C.pusilla, Grube. DESCKIPTION OF THE SPECIES. UNLESS otherwise stated, the references to Professor G. 0. Sars are to his " Crustacea of Norway," Vol. L, Amphipoda, 1895 ; those to Mr. Stebbiug (Eev. T. K. R.) are to his ' Challenger ' Report ; and to A. 0. Walker, to the Amphipoda of the ' Southern Cross ' Antarctic Expedition, Jouru. Linn. Soc., London, Zoology, Vol. XXIX. (1903), pp. 38-64. The classification of the species is, as far as possible, in accordance with that of Professor G. 0. Sars, in the " Amphipoda of Norway." After the completion of this memoir (on October 30, 190G) I received, through the kindness of the author, the Rev. T. R. R. Stebbing, F.R.S., a copy of his invaluable work on the Amphipoda Gammaridea, written for "Das Tierreich." As this will be indispensable to all systematic workers on the Amphipoda, and as it contains full references to all species described and published 6 A. 0. WALKER. up to May, 1906, I refer my readers to it where my references are insufficient. The nomenclature of the genera and species has been corrected to correspond with it. I have not thought it advisable to give synonymic lists of the older species, as I have often found these to be sources of error, owing to mistaken identifications. The following terms are used in the descriptions : — " Pleon " = metasome, G. 0. Sars ; the first three abdominal segments. " Urns " = urosorne, G. 0. Sars ; the last three abdominal segments. " Ocular lobe " = lateral angle of the head. " Appendage " = secondary or accessory appendage of the upper antennae. In the peduncle of the antennae, the " first joint " is the antepenultimate ; in the limbs it is the basipodite. The measurements are from the tips of the uropods to the base of the antennae, when the amphipod is straightened. FAM. VIBILIID^, CLAUS. VlBILIA PROPINQUA. Vilrilia propinqita, Stebbing. From lat. 54° 01' S., long. 170° 49' E. (27 Dec., 1901) to lat. G9° S., long. 174° E. (7 Jan., 1902); many specimens. The 'Challenger' specimens were taken in lat. 25° 30' N., long. 130° E. It has recently been recorded by Mr. Stebbing from the Bay of Biscay.* The genus Vilrilia has been partly revised by Herr Vosseler,f but his paper does not include the following species : — 1892. 1. V. erratica, Chevreux, Bull. Soc. Zool. de France, I7me annee, pp. 32-35. 1896. 2. V. bovalln, Bonnier, Camp, du Caudan dans le Golfe de Gascogne, Ann. University de Lyon, p. 612, PI. XXXV., fig. 3. Hit 10. 3. V.hirondellei > chevreux> Camp. scient. de 1'Hirondelle (1885-8), Fasc. XVI. °f. . ( Amphipodes, pp. 125-134, Pis. XV., XVI. 5. V. (/rand-worms ) Of these No. 1 is distinguished by the wrist of the second gnathopods being without the usual process. Nos. 3 and 4 belong to Bovallius' division, in which the lateral angles of the last urus segment are not produced backwards. No. 3 is said to be very near to V. matrix, Bov., but distinguished by the presence of a rostrum (which, according to Vosseler, occurs also occasionally in V. viatrix], the rounded form of the epimeral plates of the first and second pleon segments, the partial coalescence of the two last urus segments, and the great length of the carpal process of the second gnathopods. No. 4 is characterised chiefly by the large size of the teeth on the palmar margin of the first gnathopod. No. 5 has the angles of the last urus segment produced in "deux petits prolongements late'raux, larges et arrondis." In the present collection * Trans. Linn. Soc. Zool., 2nd Ser., Vol. X., p. 31. t Aiuphipoclen d. Plankton Expn. 1 Toil. Hyperiidea, Mitt. Koniglich. Nat. Kabinet, Stuttgart, 1901. AMPHIPODA.' 7 is a female V. propinqua, of 12mm., with seven or eight young, 3-5mm., which agree with V. antarctica, Stebbing, thus confirming Vosseler's opinion (up. clt., pp. 118 and 120, note). These were taken in the steamship 'Morning,' lat, 67° 5' S., long. 179° 30' E. FAM. CYLLOPID^E, BOVALLIUS. CYLLOPUS MAGELLANIOUS. Uyllopus mag ell an if us, Dana. From lat, 51° 58' S., long. 170° 03' E. (26 Dec., 1901) to "past Cape Adare " (11 Jan., 1902) ; several specimens ; length 12-1 4mm. FAM. HYPEKIID.E, DANA. HYPERIA GAUDICHAUDI. Hyperia fjaudichaudi, M. Ed\v. W.Q.,* 25 Dec., 1902, 6 fm., one young ; W.Q., 6 and 7 May, 1903, one female, 25mm., one male almost as large, and an immature male, 16mm. ; W.Q., 16 June, 1903, 15 fm. , one female, 10mm. ; W.Q. , 5 May, 1904, 10 fm., one immature female and two young. HYPERIA MAORONYx.f (Plate 1, fig. 1.) Hi/peria macronyj; A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (19oG), p. 452. S.E. of Coulmau I., 22 Feb., 1904, six specimens, immature, length of largest 10mm. AV.Q., 16 April, 1903, 5 fm., one specimen. W.Q., 18 May, 1903, lOfm. ; W.Q., 1 Aug., 1903, 10 fm., eight specimens. Head shorter than the first two segments. Eyes occupying the entire head Segments all free ; the three pleon-segments with a tooth on the hind epimeral angle. Carpal process of the first gnathopods rectejiini/ flu1 middle nf tin1 hind inarn/iir./i !* ovate, f.esx tli/ni tiriee UN foil;/ UN //•/u fourth pair are subeqiud to the third mid iiJun/f one-fifth lonijer than thefifth. Dactyli as in preceding pairs. First uropods reaching to the end of the third, second a little shorter. Third uropods: Peduncles broad, one-third longer than the rami, which are sub- equal, wide at the base, and acutely pointed ; the outer edge of the outer ramus smooth the rest unequally serrate. Tel son equilaterally triangular, barely reaching the middle of the peduncle of the third uropods. This species in the length of the perseopods and the relative proportions of the last three pairs approaches Parathemisto, with which it also agrees in the mouth-organs, but the widely expanded and produced wrist of the first gnathopods does not agree with either G. 0. Bars' or Bovallius's* definition of that genus. Length 10mm. HYPEROCHE LUETKEOTDES. (Plate -1, fig. 2.) Hyperoche lutkeiiides, A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (1900), p. 453. Lat. 57° 25' 30" S., long. 151° 43' E. ; one male, length 12 mm. Like Hyperoche liltkeni, Bovallius,f except in the following respects : — In the second pair of perseopods (fourth pair of Bovallius) the hind margins of the fourth and fifth joints are not serrate. In the third pair the fifth joint is curved. The telsoii is triangular, with rounded apex, wither loni/er than, tin1 /.ndf/i, of tin- IHIN<\ i/inl n'cichlni/ tot///' middle of t h.c peduncles of the third uropods. The maudibular palp has the third joint almost as long as the first and second united as figured by Bovallius for //. liitkeni. In this respect both species differ from G. 0. Bars' figure of If. kroyeri, Bov. [//. taiirifonuis (Sp. Bate and WestwoodJ)], in which the third joint is shorter than the second.§ In the first pair of perseopods the hind margin of the fourth joint is prolonged in the form of a strong serrate tooth ; in the second pair the tooth is smaller and not serrate, but the curved portion of the end of the joint between the tooth and the base of the fifth joint is so. HYPERIELLA DILATATA. HyperieHit. i/i/ntntti., Stebbing. Young specimens, abundant at W.Q. from Nov. to July, length 8-9mm. * Bovallius. Amphipoda Hyperiidea, Part 2 (1889), p. 129. t Bovallius, Amphipoda Hyperiidea, Part 2 (1889), p. 97, PI. VII. t British Sessile-eyed Crustacea, Vol. 2, App., p. 519. § Mi. W. M. Tattersall, who has kindly examined specimens of H. tanriformis from the W. of Ireland for me, informs me that the palp in the male resembles Bovallius's figure of H. liltJeeni, while that of the female agrees with Sars' figure. A.MPHIPODA. EUTHEMISTO GAUDIOHAUDI. I//, (Jiuirin. Abundant from Lit. 54° 01' S., lung. 170° 49' E. to lat. 63° 04' S., long. 175° 43' K, mostly young — a female with ova measured 15mm. FAM. ANCHYLOMERID.E, BOVALLIUS. EUPRIMNO MACROPA. nuicrojw, Guerin. One specimen, length 16mm., 26 Feb., 1904. FAM. HYPERIOPSID.E, BOVALLIUS. HYPERIOPSIS AUSTRALIS. (PL 4, fig. 3.) ix ti/ixtralix, A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (1906), p. 454. W.Q., 16 June, 1903, 15 fin. ; one. Differs from JI. Vi'n /ni/ii, G. 0. Sars (Norweg. N. Atlantic Expn., p. 231), in the following points :— The lower margin of the head is obliqur. The first segment of the urosome has a deep dorsal depression ; the second segment is the longest of the three. The third joint of the first and second perseopods is not quite twice as long as the next two united, and is about the same width, i.e., the margins are parallel, the distal three-fourths of its length. In the last pereeopods the jointing is indistinct, the very long third (or fourth) joint is finely serrate and spiuulose. Tliffirxt mill xi'i-iniil ni'iipods arc l>irin>us. In his definition of the genus Sars says that they are " simple, two-jointed," but as the rami cling closely together this might easily be an oversight. The single specimen was not dissected (nor, probably, was Sars'), but the maxillipeds are evidently of the Gammarid type. Bovallius (Amphipoda Synopidea) has placed the genus in his tribe of Synopidea under the family Hyperiopsidse. FAM. LYSIANASSID.E, G. 0. SARS. CHEIRIMEDON FOUGNERI. Cheirimedon fougnetri, A. 0. Walker. \\.i)., 8 Aug., 1902; No. 2 D., 4 fm. ; one. W.Q.. 1 Dec., 1902; Hut Point (123), one young. CMKIIUMKIMIN HANSOM. /ixinii, \. <>. \Valkur. ( 'ape Adare, 24 Feb.. 1904; Laminaria roots, i:!-2(> fm. : one, 4 mm. IUIIL;. 10 A. O. WALKEU. AVALDECKIA OBESA. (PI. 2, fig. 4.) WaMerkia ol)esa, Ckevreux. Expn. Antarctique Fran9aise (1906), p. 13. Churrntia obesa, Chevreux, Bull. Soc. Zool. de France, Vol. XXX. (1906), p. 163. W.Q., 17 May, 1902, two ; 4 Oct., 1902, off Castle Rock (107), 3 ; 27 Aug., 1902, two (one adult male) ; 5 March, 1903 (159), one large, one young ; 10 March, 1903 (160), one large. Female, length 18 mm. Body tumid : First four side plates at least twice as deep as the segments, the fourth wider at the lower margin than deep, and greatly extended behind to the hind margin of the side plate of the third perseopod ; this is large, convex, and subquadrate, widest below, angles rounded. The posterior angle of the first pleon segment is rounded ; that of the second acute ; the third has the hind margin elevated dorsally in a blunt tooth, the posterior angle upturned and sub-acute, the hind margin of the epimere hollowed out just above it, and thence convex. The first segment of the urus is carinate, the hind margin dorsally elevated in a recurved point. Head scarcely produced in front, a little longer than the first segment, speckled with red ; ocular lobe produced to an acute point reaching to the end of the first joint of the upper antenme. Eyes large, dark, elongate-reuiform. Upper iinteimse a little longer than the head, reaching the middle of the flagellum of the lower ; first joint as long as the flagellum, second very short, third almost covered by the second ; flagellum twelve-jointed, the first joint longer than the next two, setose ; appendage seven-jointed, reaching beyond the middle of the flagellum. Lower anteiinse : The first joint the shortest, the second the longest, curved and widening distally, the second and third together subequal to the twelve-jointed flagellum. In the male this reaches to the urus. Mandibles : Palp robust ; first joint about half as long as the second, which is rather longer than the third, the anterior margin of which is convex for one-third its length, then straight and fringed with set*. First inaxlllse as in So&tnies vahlii (Kroyer), except the inner plate, which has four or five unequal plumose setae. Episto-ine with both lobes rounded. Miixillipeds with the inner plates squarely truncate, with rather long setse on the ends and inner margins. First ynatliopods : Side plates more than twice as deep as wide, oblong, with the front margin obtusely angulated near the insertion of the first joint, angles rounded. First joint wide, and as long as the remainder ; wrist shorter than the hand and wider than its base. The hand is simple (not subchelate), tapering to the base of the strong curved dactylus, and setose on the hind and distal half of the front margins. Second i/uiif/iopods : .First joint fully as long as the remaining joints together; wrist longer and rather narrower than the hand, the hind margin of which is a little produced ; dactylus distinct. AMI'llll'ODA. II First peraeopods : Side plates URITOW, widening distally, curved. Coxopodite distinct, about one-third the length of the side plate. First joint subequal to the next two, widening distally ; third joint rather wider at the distal end than the first at the same point ; second, third, and fourth setose, fifth spinous on the hind margin. Second perseopods : Like the first, except the side plates (see back). Third perseopods: Side plates us deep as the leg is long, widening below, the hind margin angulate below, the front rounded. First joint wider than long, with the hind margin excavate and setose above and obscurely crenate below ; hind margin of the third joint produced to the middle of the next and terminating in a spiuous point ; the front margin of all the joints except the first is armed with short spines. Fourth perseopods : First joint subovate, very obscurely crenate behind. Fifth perseopods: First joint much wider than that of the fourth pair, the hind margin distinctly crenate in the middle. First and second uropods : The peduncles as long as the outer rarni, the inner rather shorter. Third uropods : Kami rather longer than the peduncles, the outer rather the longer, with spines on the outer and long setae on the inner margin. Telson cleft nearly to its base, reaching to the middle of the rarni of the third uropods. ARISTIAS ANTAROTICQS. (PI. 3, fig. 5.) Aristias aiitarcticus, A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (r.inii), p. 454. W.Q., 28 Feb., 1902, Millurdo Bay, 20 fm., one, length 15 mm. ; 1)., 5 June, 1902, one smaller. Body moderately compressed, without carinae or teeth. Head shorter than the first segment ; ocular lobe produced to the end of the first joint of the upper antennae, rounded at the apex. Eyes large, dark, expanded below. Body-segments increasing in length backwards. First four side-plates about as deep as the segments, the first concealed by the second ; the fourth moderately pro- duced behind ; the fifth much wider than deep. Posterior angle of the third pleou segment produced backwards, acute. First urus segment depressed in front ; second and third almost concealed by the first, and perhaps coalesced. Upper and lower antennae subequal, scarcely reaching the end of the third segment. U/ijier niiti'imse : First joint rather longer than the second and third, the lower margin projecting distally ; second twice as long as the third, lower margin projecting. Flagellum ten-jointed, the first joint setose, as long as the next three joints, which are distally setose. Appendage five-jointed, the first the longest, the rest subeijiial. Lower antennse : First joint twice as wide as long ; second and third subequal, about three times as long as the first ; flagellum ten-jointed. 12 A. O. WALKER. Mandibles as in .1. ncglcctus, Hansen,* but the projection from the molar tubercle, which appears to be membranaceous, is less prominent. The third joint of the palp is straight. First and second maxillse as in A. neylectu*. Maxillipcds as in A. neglectus. First gnathopods : Side plates small, rather wider than deep. First joint as long- as all the rest, four times as long as wide. Wrist longer and wider than the hand, unequally setose on the hind margin. Hand not subchelate, narrowing distally, the front margin convex, the hind slightly concave, spinulose along its entire length, with four spines at unequal intervals. Second gnathopods : Side plates semi-oval, extending to about one-third of the first joint. First joint subequal to the next three united, widening to about one-fourth of its length from the distal end, then narrowing. Wrist longer and wider than the hand, the hind margin densely setose ; hand with subparallel margins, both setose. Dactylus well developed. First and second perseopods : Side plates rounded below, those of the second pair obtusely augulated about the middle of the hind margin. The fourth joint is about half as long and twice as wide at the distal end as the fifth ; the hind margin of the latter terminates in an acute angle. The remaining perseopods are subequal in length and structure, robust, the third joint expanded, the fourth with both margins produced downwards ; the hind margins of the first joints in the third and fourth pairs are smooth, except the lower part, which is obscurely crenate ; in the fifth pair the whole margin is serrate. First and second uropods : Peduncles subequal to the outer mini, inner rather longer ; all parts sparsely spinous. The first pair extend beyond the second and these beyond the third. Third uropods : Inner rami lanceolate, as long as the peduncle, and reaching to the end of the first joint of the outer ; margins finely spinulose. Telsoii about as wide at the base as long, cleft about two-thirds of its length, divisions dehiscent, rounded. Both specimens had the third and fourth peraeopods turned up over the back. ORCHOMENE GONIOPS.| (Plate 3, fig. 6.) Orchomene goniops, A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (11)0(1), p. 455. W.Q., 21 Aug., 1903 ; two specimens, probably immature; length 5 mm. Body-segments increasing in length backwards. First four side-plates deeper than the segments, narrow. Tliird pleon-segment with a small postero-dorsal carina and hind and lower margins straight, the former crenate, the posterior angle rather less than 90°. * Vidensk. Meddel. 1887 (1888), p. 67. f yavla, angle ; &\jr, face. AM PHI POD A. 13 Plead shorter than the first segment ; ocular lobe hroad/i/ triangular, />ro/l need beyond flic end of the //edunc/i- of tin' ii/>ji, r /ntfennse. Ei/e moderately large, oval, dark. U]>i>er uttfi'itiite : First joint three times as long as the next two united, naked. Flagellum 13- 14 -join ted, the first joint as long as the next three, sparsely setose on the upper side. Appendage 5 -jointed, the first joint the longest, the third the shortest. Loireraiitennse rather longer than the upper ; peduncle reaching the end of the third joint of the rlagellum of the upper ; first joint the longest, second the shortest. Fir*t gnathopods: Side plates narrowed and rounded below; wrist two-thirds of the length of the hand, which is about twice as long as wide, with parallel margins, setose ; palm rather oblique, convex, crenulate, defined by a spine. Second gnathopods as in Orchomene humilis (Costa) [= 0. l>atei, Sars]. Third perseopods : Side-plates wider than the depth in front, with the usual posterior lobe ; first joint about half as large as the side-plate, deeper than wide ; hind margin convex, serrate, produced down to the middle of the third joint ; this is much produced behind and downwards. The fifth perseo/todx have the first joint i/earh/ tir'w UK UK tcidc, and IOIII/IT than the re*f of the joints, including tin' dactylus, toiji'ther, otherwise like the third pair ; the dactyli of all the perseopods are very short. Thefirxt itropod* are subequal in extent to the second, exceeding the third ; the peduncle is one-fourth longer than the subequal rami, all the parts very spinous on the upper margins. Second pair less spinous. Peduncle in the third pair rather longer than the outer ramus : inner ramus not nearly reaching the end of the first joint of the outer, its inner margin minutely serrate. Telxon entire, deeply concave above, the end truncate unfit two setules : it extends beyond the end of the inner rami of the third uropods. The difference between the telson of this species and that of the female 0. luonilix is only one of degree, as the truncate margin is slightly concave. ORCHOMENELLA PINGUIDES. Orchomeitella piiiijuides, A. 0. Walker. "W.Q., March to October,1902 ; ten, 14^ fm. ; length 10 mm. 0. FRANKLINI. O.franklini, A. 0. Walker. AV.Q., 15 June, 1902 ; D net, nine, various sizes, length of largest 6 '5 mm. 0. CHELIPES. (PI. 4, fig. 7.) 0. chelipes, A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (Him;), p. 4.M;. W.Q., 28 Feb., 1902 ; eight,, 10 fin. Both/ moderately compressed ; first and second segments subequal to the head and each other, remaining mesosome segments rather longer and subequal. First four side- 14 A. 0. WALKER. plates but little deeper than the segments. Hind margin of the epimere of the third pleon segment forming a rounded right angle with the straight lower margin. First uru's segment as long as the remaining two, carinate ; second shorter than third. Head : The ocular lobe reaching the end of the first joint of the lower antennae, rounded at its apex. Eyi'8 large, wide-oval, dark red in spirit. Upper antennae : First joint about three times as long as the next two, naked ; third shorter than the second. Flagellum in the female 11 -join ted, the first as long as the next two, with a few long setae below. Appendage 4-joiuted, the first twice as long as the second, which is subequal to the third, the fourth minute, the whole very sparsely setose. Lower antennse slightly longer than the upper ; flagellum 12-jointed, subequal to the peduncle. Mouth organs as in 0. intna (Kr.). The maudibular palp strong, with the second joint twice as long as the third. First gnathopods : Side plates widening downwards, rounded in front, straight behind. First joint almost as long as the rest united ; front margin of the wrist rather shorter than that of the hand ; hand rather narrower than the wrist, slightly curved, the hi IK I margin produced distally xo ft ft to form an imperfect chela with the dactylus ; the oblique palm is finely pectinate and defined by two spines ; the hind margins of the third, fourth, and fifth joints are densely fringed with short setse. Second gnathopods rather stout ; side plates oblong, widening below. First joint about twice as long as the second, which is longer than the third ; this has the hind margin densely pilose ; wrist tumid, much longer and wider than the hand, the hind margin convex, scabrous ; front margin straight, densely setose ; hand densely setose, with a few strong curved and serrate spines over the insertion of the dactylus. Second persenpods : Side plates moderately produced and angulate behind. Third, fourth, and fifth perseopods of similar structure, increasing in size suc- cessively ; the side plates of the third pair are wider than deep, and much larger than the first joints. The first joints in the three pairs are wide and obscurely crenate behind. First uropods extending a little beyond the second, and these beyond the third ; inner ramus of the third not reaching the last joint of the outer. Telsftn barely reaching the end of the peduncle of the third uropods, deeply notched. Recognisable by the peculiar form of the first gnathopods. ORCHOMENOPSIS ROSSI. Orchomenopsis rossi, A. 0. Walker. This species was taken in enormous quantity throughout the year, and is doubtless the one to which Mr. Hodgson refers in his " Preliminary Report," p. 398, as being "commonly taken 10,000 to 30,000 at a haul." It is noteworthy that it has not been AMPHIPODA. 1 5 takeii either l>y the 'Discovery' or 'Southern Cross' north of lat. 77° 50'. Male specimens with the lower antennas developed in the manner supposed to indicate sexual maturity are very scarce, yet in a gathering from Castle Rock Seal Hole, W.Q., 14^ fm. (no date), there are a number which, though only 15 mm. long, have the flagella with 36 joints well furnished with calceoli ; and from Hole 0, W.Q., 23 Feb., 1903, 130 fm. (153), there is a probably adult male of 25 mm., which appears to be the maximum size. There is some variability in the form of the third pleon segment, the hinder angle of which is less rounded in some specimens, especially the largest, than in others. Mr. Hodgson writes as follows :— "This species was not regarded with favour when we were in Winter Quarters, and it is a matter of considerable regret that its seasonal development was not looked for ; its migration it was impossible to follow. It occurred first in considerable numbers on the 17th May, 1902, when the winter was well advanced. On that occasion the trap was hauled from 56 fathoms about 4.0 p.m. and then it was so dark that I was obliged to return to the ship for a lantern. The trap contained about 10,000 of these amphipods. A thousand individuals were counted, the volume ascertained, and this formed the basis for the present estimate of number and for future occasions. Four fish were in the trap, one of them had been reduced to an absolute skeleton ; on another the amphipods hung by their ' teeth ' in a compact mass, completely concealing their victim. Its skin had disappeared, and I judged also about a millimetre of flesh, but the animal was still alive ; the other two fish were presumably waiting their turn. " From that date until 25th October, 1902, this species was taken generally in numbers varying between 10,000 and 30,000 at a haul, and this at all depths to 125 fm., which was our practical limit for ordinary work. Two or three times a trap was used in 173 fm., in July and August 1902, but not many amphipods were obtained — 100 or so at a time. These animals swarmed over the bait to such an extent as to make it obvious they kept other animals away ; otherwise the number of other animals captured was unaccountably small. Under these circumstances the presence of this amphipod was regarded as a nuisance, and as a large stock had been preserved, further captures were generally left on the ice at the mouth of the hole. My experience at the holes soon made it perfectly clear that there was no small mortality among the seals through their not being able to get to a breathing-hole in time during their wanderings, and thus affording a substantial food supply for predaceous crustacea. I came to the conclusion that these amphipods travel about the sea bottom in vast hordes in search of food, a conclusion further accentuated by the fact that from 25th October to 27th December, 1902, they completely disappeared from all the traps; stationary traps were not used during the same period of 1903. From October to January is the seals' breeding season, and at this time they remain, for the most part, close inshore. The place nearest the ship where they congregated most was among the pressure ridges at Pram Point. These ridges are formed by the 'Barrier' ice intruding into the Sound between White Island and Cape Mackay and pressing against the laud at Pram Point. As the ice did VOL. III. G 16 A. 0. WALKER. not go out during the season of 1902-3, the principal ridge became more than a mile long, the ice being pressed up to a height of twenty or thirty feet at the point of greatest pressure. Considering that the mortality among the seals would be much increased during the breeding season, it occurred to me that the amphipods might have migrated close inshore, more especially to Pram Point, as an area where a super- abundant supply of food might be obtained. I went to investigate this matter, but the seals had made their holes among the irregular blocks of ice piled up in a confused manner. I found that the hole from the surface usually led on to a platform some two or three feet below ; the hole which completed the passage through the ice had no relation to the one above, and was generally at some distance from it, and quite invisible from my point of view. As it turned out, I could not get a trap down any of the holes, so that the presence of these amphipods on the breeding-grounds of the seals is uncertain, and no explanation of their desertion of the traps in deeper water is forthcoming." TRYPHOSA MURRAYI. Tryphosa murrayi, A. 0. Walker. T. adarei, A. 0. Walker. This is another abundant species, though not nearly so much so as 0. rossi. The largest female measured 30 mm. It appears to occur from Cape Adare to lat. 77° 50', and was taken at the Winter Quarters throughout the year. The examination of a large number of specimens has convinced me that the characters relied upon for the separation of T. murrayi and T. adarei, viz., the form of the hind margin of the third pleon segment and the cariua on the first urus segment are very variable, and I have therefore united them. TRYPHOSA KERGUELENI. Lysianassa Tcertjuekiii, Miers. Hippomedon Jcergueleni (Miers), Stebbing. Hoplonyx Icergwleni (Miers), A. 0. Walker. Cape Wadsworth, 8-15 fm., 15 Jan., 19 02, one, small ; W.Q., 15 June, 1902, one, length 13 mm. ; W.Q., 20 Sept., 1902, Castle Eock, 14£ fm., three. URISTES GIGAS. Uristes ffiffas, Dana. Tryphosa antennipotens, Stebbing. Past Cape Adare, 11 Jan., 1902, one specimen. PODOPRIONIDES. Podoprionides, A. 0. Walker, Ann. and Mag. Nat. Hist. XVII. (1900), P- -*57. Resembles Podoprionella, G. 0. Sars, in the chelate first gnathopods and the deeply serrate first joints of the last three perseopods, but differs in the less compact AMPHIPODA. 17 body, the structure of the mandibular palp and of the outer ramus of the third uropods. From Podoprion, Chevreux,* it differs in having the h'rst joint of the fourth and fifth perseopods serrate like the third. PODOPRIONIDES INCERTA. (PI. 5, fig. 8.) Podnpnonides mcerl/i, A. 0. Walker, Aim. and Mag. Nat. Hist. XVII. (_KK)6), p. -157. W.Q., 29 Aug., 1902, Hole 12, D net, one specimen ; length 2 mm. Body not wry compact ; the anterior side plates small. Upper antennse reach in;/ a little beyond the peduncle of the lower; appendage 2-jointed, the first twice as long as the second, which has a tuft of very long setae at the extremity. Loir< r anfennte: Peduncle stout, margins of third joint produced. Mandibular palp with the third joint moie than half as long as the second, narrow, pectinate. First gnathopods : Side plates less than half the length of the first joint, rounded in front, straight behind, with a notch and a spine above the angle. First joint rather longer than the remaining five, widening clistally ; second and third joints subequal ; wrist subequal to the hand ; the hind margin of the hand is short, conre.c and i>rolunoa. Palp of the firxt nutxillse two-jointed. First gnathopods distinctly subchelate. Ti'lson large, entire, oval and net in a vertical plane on its longer nl/> has the second joint wider and about one-fourth longer than the third, being widest about one-third of its length from the base. OK. OALMANI. (PI. 6, fig. 12.) Of. ,',/hnani, A. 0. Walker, Ann. ami Mag. Nat. Hist. XVIII. (190(i), p. 15. Coulman Island, 13 Jan., 1902, 100 fm., two females. Flagon Point, 23 Jan., 1902, one young. Barrier, 29 Jan., 1902, 100 fm., one. AMPHIPODA. Female : Body scarcely compressed laterally. Mesosome segments very short , subequal, the first with a transverse fold. First pleon segment about twice as long, the second shorter, the third much longer than the first ; the last mesosome and first two pleon segments with a dorsal tubercle near the middle ; the third pleon and first urus segments with a shallow cariua ; hind margin of the third pleon segment rounded. First four side-plates as deep as the segments. Head : Rostrum shorter than the rest of the head and reaching the end of the first joint of the upper antennae, the lower margin scarcely concave ; the front sulcate, not carinate. Eyes contiguous, occupying the greater part of the rostrum, varying from red to brown. Upper antennse not quite reaching the end of the second joint of the lower ; the first joint rather longer and twice as wide as the second, widening distally ; the second twice as long as the third ; first and second with tufts of plumose setae. Flagellum ten-jointed, shorter than the peduncle. Lower antennse: First joint wider than long, setose ; second stout, longer than the third, which has a long spine near the middle and another at the distal end, both on the lower margin. MandMes : Primary cutting edge with two short blunt teeth, secondary with a long and a short tooth, molar tubercle bicuspidate ; first joint of the palp very short and obconical ; second subequal to the third in length, but more than twice as wide near the base; both joints with long spine-like setae on the front margin. Third perseopods : First joint oblong-oval, the front margin somewhat produced, both margins with long setas, on the distal half; third joint almost as wide as the first, densely setose. Fourth perseopods : First joint ovoid, the hind margin denticulate, sparsely setose ; the front margin with longer setae which are plumose at the lower angle, otherwise as in the third pair. The dactyli in all the peraeopods except the last (which are broken in all the specimens) are almost as long as the fifth joints. The gnathopod* and rest of the animal agree with (E. r,/u n't/, A. 0. Walker, Aim. and Mag. Nat. Hist. XVIII. (1!)OG), p. HI. Jan. 22, 1902, 500 fm., three; W.Q., 4 Sept., 1903, Hole 12, one. All the segments of mesosome and pleou, with the exception of the first two segments, of which the first is twice as long as the second, armed with lateral teeth, increasing in length backwards, with longer dorsal teeth, curved and directed upwards and backwards ; those of the last mesosome and first two pleou segments the longest. AMPHIPODA. 25 First two segments of the urus with an upright dorsal tooth, that on the first segment the longer ; the third segment with a lateral carina, which is turned up in a sharp tooth. First three side plates narrow, acutely pointed below, the first straight, second and third curved ; the hind margin of the fourth forms an irregular crescent with acute points ; the fifth has a long acute tooth directed backwards and outwards, reaching the hind margin of the sixth segment ; the sixth has a small tooth ; the seventh unarmed. Posterior angles of the epimeres of the pleon segments produced and acute. Head : Lower margin of the ocular lobe produced forward in an acute tooth. Rostrum almost horizontal, slightly deeurved, and much longer than the rest of the head. Eye large, round-oval, almost filling up the ocular lobe, colourless in spirit, I'/ijur itiifi'iinse shorter than the lower; first joint with a subequal distal tooth on each side, reaching nearly to the distal end of the lower margin of the second joint, which is subequal to the first, and has two long subequal distal teeth on the upper side, reaching to the seventh joint of the flagellum ; third joint about half as long as the second, with a small distal tooth on the lower margin. Flagellum 32-juinted, slender. Loii-fr anti'iuise : Basal joint with four or five unequal teeth ; first joint very short ; second and third more than twice as long, subequal, the former with a small distal tooth below. Flagellum slender, reaching in the largest specimen to the fifth segment. Mouth organs and maxillipeds as in E. cornigera. First and second gnathopods almost alike, more slender than in E. cornigera, and almost exactly like those of E. parasitica, M. Sars. First and, second perceopods : First joint subequal to but wider than the third ; fourth joint about half as long as the third ; fifth considerably longer than the fourth. Third perceopods: First joint rather longer than and twice as wide as the third, the hind margin concave, with a rounded protuberance at the proximal end and a large, very sharp tooth at the distal end directed backwards ; front margin concave in the middle ; front margin of the second joint produced downwards in a small tooth ; third joint acutely produced behind. Fourth perseopods : Hind margin of the first joint convex in the middle, otherwise like the third pair. Fifth perseopods : First joint wider than that of the fourth pair, the margins more convex above, but the hind one concave above the strong and sharp distal tootli ; front margins of first and second joints not produced. The uropods are all subequal in extent ; the second pair has the outer rarnus one- third shorter than the inner ; in the first and third pair the outer rami are scarcely the shorter ; the peduncles of the third pair have the upper margins produced behind in an acute tooth, and are about one-third of the length of the rami ; these are long and narrow, lanceolate, with a few small spines on both margins. H 2 2G A. 0. WALKER. The telson narrows distally, the sides are slightly convex, and the divisions formed l>y a notch extending to about one-third of the length are subacute. Length 33 mm. This species has a superficial resemblance to Acanthozom (Boeck.*), from which it differs in the shape of the head, and Acanthechinus (Stebbing), from which it differs in the head, mandibles, gnathopods, etc. Both these genera have the telsou entire. EPIMERIELLA. Epimeriella, A. 0. Walker, Ann. and Mag. Nat. Hist. XVIII. (190G), p. 17. , Body smooth, without dorsal teeth, except in the first segment of the urus. Head with a very small rostrum. Fifth pair of side plates small, oblong, wider than deep, without a projecting process. Mandibles with the molar tubercle imperfectly developed. Third and fourth pairs of perteopods much longer than the fifth. Otherwise like Epimeria. EPIMERIELLA MACRONYX.| (PI. 9, fig. 15.) Epimeriella macronyx, A. 0. Walker, Ann. and Mag. Nat. Hist. XVIII. (1906), p. 17. W.Q., 29 May, 1903, Hole 4, 5 fm., two ; W.Q., 1 June, 1903 ; Hole 8, 10 fm., three; 26 Feb., 1904 (269), one. This last measured 25 mm. ; the rest were young, measuring only 6 mm. Hmd slightly produced in front. Eyes large, round, oval, prominent, colourless in spirit. Mesosome smooth, first and third segments subequal, and much longer than the second ; remaining segments increasing in length successively. First three side-plates about as deep as the segments, narrow, convex, and pointed below, fourth deeper than the others, narrowing below in a curved point, with the upper posterior angle produced under the fifth side-plate in an acute tooth ; fifth, small, transverse, oblong, with rounded ends. Pleon with an obscure dorsal carina ; hind and lower margins of the third segment straight and forming a right angle. First segment of the urus dorsally depressed in front, and with a postero-dorsal tooth. Upper antennse : First joint more than twice as long as, and much wider than, the second ; third shorter than the second and subequal to the first joint of the flagellum, which has about twenty joints. Lower antennse subequal to the upper ; first joint very short ; second and third subequal, barely reaching to the end of the second joint of the upper. Mandibles : Molar tubercle imperfectly developed ; primary and secondary cutting * Skandinavske og Arktiske Ainphipoder, 187G, p. 229 ; also G. O. Sars. t From the great length of the dactyli of the third and fourth perseopods. AMP HI POD A. 27 edges dentate ; spine row long, of about twenty spines ; the palp, which is set on in front of the middle, is longer than the mandible ; the first joint about one-third as long as the second, which is subequal to the third. One of the mandibles appears to be without a secondary cutting plate. First mnxillse: Inner plate with about 12 plumose setae on its inner margin. First (jnathopodx : First joint stout, rather longer than the side-plate, and subequal to the wrist and hand united ; these are subequal to each other, the wrist rather the wider ; the hand is oval, the palm undefined, pectinate ; the whole hind margin sparsely and unequally spinous. Dactylus with 5 spines on the inner margin. Si'C0. W.Q., 24 Sept., 1902, Hut Point, one, large ; 24 Aug., 1903, Hole 12, D-net, three, large, 30 mm., and about twenty-five, young ; 26 Sept., 1903, Hole 12, D-uet, one, about 45 mm. long and 15 mm. across the back. First segment of the mesosome longer than the second ; the next four segments are longer than the second and subequal ; the posterior angles of the first two are almost rio-ht angles, and of the next four acute. The fifth segment has sometimes a few small £> O ' teeth on the hind margin ; the sixth has more, and the seventh is clorsally depressed, and is longer than any of the other segments in the middle, but greatly narrowed down- wards, with the hind margin more coarsely dentate. The pleon segments have strongly dentate, dorsal carinse, with smaller teeth on each side, and on the hind margins ; the posterior angle of the second is acute and upturned, and that of the third similar, but longer, and with a much longer curved tooth above it. The first urus segment is as long as the two next united, and has a dorsal depression followed by a group of upright teeth ; the second and third are smooth, except for a tooth on each side of the telson. The first three pairs of side-plates narrow downwards to a point, the second and third curved ; the fourth, fifth and sixth have a strong tooth with serrate edge directed outwards. The number of teeth appears to vary considerably in different specimens. Head : Rostrum as long as the rest of the head, acute, decurved ; ocular lobes rounded ; eyes prominent, round, colourless. Upper antennae : First joint with two distal teeth on the upper side ; second joint with a serrate tooth reaching almost to the end of the first joint of the flagellum on the upper margin, and a short one on the lower ; third joint short. In a young specimen a rudimentary appendage was seen, but in a larger (though not adult) this was only indicated by two setse. First joint of the flagellum as long as the next three.* Lower antennse subequal to the upper ; second and third joints subequal ; the three peduncular joints have the upper margins produced ; the basal joint has a prominent curved tooth on its upper side. Mandibles, without molar tubercles, different ; one, having the simple cutting- edge oblique, obscurely dentate, with a tooth at the lower angle ; the other having the cutting edge more strongly dentate, with a peculiar secondary apparatus in the form of a hollow chitinous cylinder with a smooth periphery. First joint of the robust palp shorter than the second, which is subequal to the third. * In the specimen figured the antenna was curved upwards. AMPHIPODA. 29 First maxillae normal. Mcucillipeds as in /. pacijlca, except the inner plates, which are oblong and almost as wide as the outer. Firxt ijiiatlinpntlx : First joint widest in the middle ; wrist rather shorter than the hand, which is chelate with short spines on the immovable digit. Second i/iintlm/Kitl* : First joint narrow, oblong, as long as the remaining joints ; wrist and hand subequal, the latter chelate with long plumose setae on the hind »in. Firxt mill *l>.'f>a has been successively allotted to " the confines of the family Leucotlundse (G. 0. Sars)," Stebbing, p. 783 ; the L>^i<-alitv as S. $ (',. STEWARDSON BRADY. dorsal margin boldly and evenly rounded, ventral evenly convex but not so fully arched as the dorsal margin. Seen from above (fig. 3) the outline is ovate, scarcely twice as long as broad, widest in the middle, rounded off in front, strongly mucronate behind. The ventral border of the rostrum is produced into a thin lamina which is partly overlaid by long closely-set hairs, and the posterior border of the subrostral sinus is similarly fringed (fig. 4). Shell-surface closely and very finely punctated throughout, smooth, except on the ventral aspect, where it bears numerous scattered hairs. Just behind the rostral sinus there is a small patch of eleven or twelve subparallel striae, and a short series of stiff hairs just within the ventral margin : a large black eye-spot just within the dorsal border at its anterior third. The shell of the male (fig. 1) is larger and more elongated than that of the female, nearly twice as long as broad, with a less pronounced rostral sinus and a much narrower and more produced posterior extremity, the eye-spot small and situated near the centre. Length of the male, 2 • 3 mm. ; of the female, 1 • 7 mm. The setse of the terminal fascicle of the antennule in the female are very short-- not more than half the length of the limb ; the second (or third ?) seta of the antennae is spinulose (fig. 8) in the female, the remaining setse are simply ringed : the secondary branch of the antenna (fig. G) is of the usual form, but has an indistinctly jointed appearance at the apex. Principal tooth of the second maxilla (female) (fig. 9) sharp and broadly triangular ; ungues of the caudal lamina (fig. 10) rather strongly pectinate in the female — but only faintly ciliated in the male. The eyes of the male (fig. 5) are pyriform, and deeply pigmented, the frontal tentacle rigid, dilated, and slightly pig- rnented at the base. Secondary branch of the antenna of the male large and strongly prehensile (fig. 7), the last joint bulbously dilated at the apex, basal joint bearing a strono-ly uncinate process. P. Antarctica was found rather sparingly in four of the gatherings taken at " No. 4 hole " in a depth of five fathoms. The shell was in all cases of a thin, membranaceous character, but I suspect that this may have arisen from the solvent action of the formalin preservative on the mineral matter. PODOCOPA. XESTOLEBERIS RENIFORMIS. (Plate L, figs. 4, 5.) Shell of the male seen from the side (fig. 4) subreniform, much narrower in front than behind, greatest height situated behind the middle and equal to half the length ; anterior extremity well rounded, narrow, posterior much wider, not very fully rounded, dorsal margin forming a continuous arch, highest behind the middle, sloping very gradually backwards and with a rather steep curve towards the front, ventral margin rather deeply sinuated in the middle. Seen from above, the outline is broadly ovate OSTEACODA. 7 (fig. 5), pointed in front, broadly rounded behind, the lateral margins very boldly arcuate, greatest width situated behind the middle and equal to two-thirds of tin- length. The surface of the shell is smooth, deep ochreous yellow in colour, with a conspicuous dark eye-spot within the dorsal margin near the front, just below and behind which there is a large irregularly shaped pellucid, sub-circular patch, and belo\v this again a series of four oblong muscle spots, arranged in a transverse curve, and in front of these two smaller spots the long diameters of which lie in the opposite direction. The left valve is the larger of the two, overlapping the right both in front and behind. Length 0'65 mm. The shell of the female is somewhat more tumid, and seen from the side has no ventral sinuosity ; it is also almost free from anterior depression, the two extremities being nearly equal in width. Two specimens only of this small species were seen, a male and a female ; the female, however, was only an empty shell and was quite colourless. The exact locality of the capture I do not know. The specimens were accidentally discovered in a flocculent diatomaeeous deposit which settled from the liquid in which the larger Cypridinidse had been preserved. The fiexuous lateral contour of the male distinguishes this from any other species of Xestoleberis known to me. LINOCHELES.* Differing from the typical Cytheridse in the greatly elongated and thread-like legs of the third pair, and in the abnormally formed copulatory plate of the male. LINOCHELES VAGANS. (Plate III., figs. 11-18.) Shell closely similar in shape to Xestoleberis; seen laterally (fig. 11) that of the male is subreuiform, greatest height situated behind the middle and equal to much more than half the length ; anterior extremity narrow and obliquely rounded, posterior very wide and evenly rounded, dorsal margin boldly arched, steeply curved posteriorly, sloping with a gentle curve to the front, ventral margin sinuated in front of the middle ; seen from above, the outline is elongated, ovate; widest in the middle (fig. 12), width rather less than half the length, narrowed and obtusely pointed in front, broader and rounded off behind. Shell-surface perfectly smooth ; colour brown. Length, 0 • 64 mm. Antennules six-jointed, very sparingly setiferous (fig. 13) ; antennae short and stout, with short apical claws and a stout urticating seta which reaches to the apices of the claws (fig. 14). First and second pairs of legs (figs. 15, 16) armed with short and stout terminal claws; third pair much elongated (fig. 17), the last joint extremely slender and much longer than the united lengths of the two preceding joints ; terminal * Aii'iir, a thread ; x>;An, a claw, I, L> G. STEWARDSON BRADY. claw very long, thread-like in its tenuity, nearly half as long as the entire limb ; external copulative organ (tig. 18) elongated, divided into two portions, the distal part pear-shaped and attached liy a narrow neck to the basal region. Of this curious form only four specimens were found ; all of them males. Three specimens from a surface netting in Lat. 49° 40' S., Long. 172° 18'30'E., and one from a netting in five fathoms, Lat. 58° 49 '45' S., Long. 154° 48' W. It is difficult to account for the presence at the surface of an animal quite destitute of swimming organs. I am disposed to think that the real habitat is probably among floating weeds, and that the extremely long hinder limb may be useful in giving a grasp of delicate algse or other vegetation. EXPLANATION OF PLATES. PLATE I. PHILOMEDES OBBICULARIS. Fig. 1. Shell of female seen from left side x 22. 2. „ „ from above x 22. ,, 3. „ male seen from right side x 30. (5. Beak and sinus of female seen from side x 84. 7. Extremity of antennule of male x 84. „ 8. Antenna of female X 50. 9. Secondary branch of the same X 120. „ UK „ of male X 120. ., 11. Miindilmlar foot of female X 100. («) Process of basal joint X 300. 12. Principal tooth of second maxilla seen from side x 210. ., 13. „ „ „ seen from front X 240. It. End of vermiform foot x 84. ., 15. Post abdominal lamina X 84. XESTOLEBERIS RENIFORMIS. Fig. 4. Shell of male seen from left side x 84. „ 5. „ „ from above X 84. PHILOJIEDES ASSIMILIS. Fig. 10. End of antennule of male X 84. ., 17. External branch of the antenna of male X 50. ., IS. Antenna of female x 84. .. 19. Mandibular foot of female X 100. (it) One of the marginal sets more highly magnified. Figs. 20, 21. Principal tooth of second maxilla seen laterally and oblii|uely X 240. PLATE II. PlULOJIEDES ASSIMILIS. Fig. 1. Shell of female seen from left side x 4o. ,, 2. „ „ seen from above X 4o. „ :i. „ male seen from left side x In. „ 4. Beak and sinus of male X 84. „ 5. Post-abdominal lamina of male X 84. G. female x M. OSTRACODA. CONCHCECIA INNOMINATA. Fig. 7. Shell of male seen from left side x 22. ,, 8. Antcnmilc and frontal tentacle of male x *l. '.I. „ „ „ female x 84. in. Internal branch of antenna of female x 84. ,,11. „ „ „ male X ,s-l. 12. Chewing process of mandible X '24(1. „ 1:5. Copulatory organ of male x 84. ,, 14. Post-abdominal lamina x 84. PLATE III. PHILOMEDES ANTARCTICA. Fig. 1. Shell of male seen from left side X 30. „ 2. „ female seen from right side X 30. „ 3. „ „ „ above x :'.n. „ 4. Margin of shell of female with subrostral sinus x *4. ., 5. Eyes and frontal tentacle of male X 55. „ 6. Secondary branch of antenna of female x UMI. :, 7. „ „ ,, male X inn. N. Portion of second seta of antenna of female with marginal spines x 320. •J. Tooth of second maxilla of female X 84. ,, 10. Caudal lamina of female x 84. LlNOCHELES VAGANS $ . Fig. 1 1 . Outline of .shell seen from left side X 84. ., 1-. ,, „ „ above X 81. „ 13. Antennule x -'in. .. 14. Antenna (apical joints) x 24n. ., 15. Foot of first pair x -In. ., 1C>. „ second pair x 240. ., 17. „ third pair X 240. „ 18. Copulatory organ X 240. ••• • I Exp. 14. LJiscove : acoda : G S E CEUSTACEA. VI -CIEEHIPEDES. Par A. GRUVEL, Maitre cle Conferences de Zoologie (Universite de Bordeaux). (1 Plate.) LES Cirrhipfedes du ' Discovery ' qui m'avaieut ete envoyes des le mois de Decembre, 1904, par le " British Museum," n'ont pu etre etudies qu'en Avril, 1906, a cause de travaux tres importants et tout-a-fait differents que nous avions alors eutrepris, en particulier de nos deux Missions pour 1'etude des Pecheries de la cote oceidentale d'Afrique. Bien que peu considerable par le nombre, cette collection du ' Discovery ' eontient une espece d'Opercules interessante, c'est un Elminius ruyosus de Hutton, et deux especes de Scalpellum, nouvelles pour la science : Se. Discovery i et So. Bouvieri. Voici. du reste, la liste de ces especes. OPERCULATA. HEXAMERIDyE. Genre Balanus, Da Costa. Une seule espece, represented par des echantillons sees, dont les pieces operculaires out entierement disparu, mais qui est certainement le Bal. psittacus, Molina, Un individu d'assez grande taille est surtout bien earacterisr. TETRAMERID.'E. Genre Elminius, Leach. Ce genre est represeute par une seule espece egalernent. Bieu que Hutton n aie pas publie de figure pour Elminius ruyosus, la diagnose assez complete qu'il en a donnd se rapporte si exactement a celle de 1'espece que nous avons eu a examiner que nous n'hesitons pas a 1'identifier. Jusqu'ici cette espece n'a e'te signalee qu'en Nouvelle- Zelande, sur les rochers du Bluff, par son auteur. Nous croyons, done, interessant de donner quelcjues figures (fig. 1-3) se rapportant a cette espece recente, tmsvoisine, comme le dit Hutton, de YElminius j'lii-iitii* <\c ( Iray. * Trans. N. Zealand Inst., xi.. 1878. p. :i28. A. GRUVEL. PEDUNCULATA. POLYASPID.E. Les deux especes qui repmseutent cette famille appartiennent au genre Scalpellum Leach, et sont. toutes les deux, nouvelles pour la science. Nous avons eu plaisir a dedier 1'uiie d'elles a M.' le Professeur Bouvier, du Museum de Paris, dont 1'extreme obligeance a notre egard ne s'est jamais lassee, et qui a bien voulu presenter au public scientifique notre " Monographic des Cirrhipedes." Quant a 1'autre, nous lui donnons le nom du navire qui a servi a la belle Expedition scientifique que Ton eoimait. ScALPRLLUM DISCOVRRYI (fig. 4-6). Dia capitulum et s'eloignant de plus en plus du cote de la base, mais jamais imbriquees. Pas de penis. Appendices filamenteuz uniarticules, a pciue plus longs que le protopodite de la sixieme pairc de cirrhes et ornes de quelques rare soies. Affinites. — Par son aspect exterieur d'ensemble et si on ne la considerait qu'un peu superficiellement, cette espece pourrait etre assez facilement confondue avec le Scalpellum nnijustuin de Prof. G. 0. Sars. Mais, examinee avec soin, on voit ({iielle s'en distingue par ])lusieurs caracteres, dont les deux principaux sont : la presence d'un umbo tres net a la carene qui manque chez Sc. . Sars. Austrodecu* is perhaps a close relation of 77///»/«, Miers, and is a curious little form with a slender and elongated proboscis, like the snout of a weevil beet le. no ehelifori, six jointed palps, and small ovigers. Au*tr»rtn« is remarkable for its spurred body and the length of its legs. Rhynchothorax *w//v///,v is another curious form ; the only other species of the genus is found in the Mediterranean, but, notwithstanding certain differences, there does not seem to be any justification for giving the 'Discovery1 species other than specific rank. M -2 T. Y. HODGSON. The remainder of the collection falls into well-known genera, and does not call for any special comment. A list is appended below of all the species now known from the Antarctic and sub-Antarctic regions, those taken by the ' Discovery ' being marked with an asterisk. The numerous islands scattered about the southern seas have long been considered to pertain to the sub-Antarctic region, and for this reason I have made the mean annual isotherm of 45° F., as indicated by Sir John Murray in the concluding volume, of the " Challenger Reports," its northern limit. This includes all that can reasonably be considered as belonging to this region, and coincides very closely with the opinion expressed by Professor P. Pelseneer in his Beport on the Mollmen. of the ' Belgica ' Expedition. For the Antarctic proper the latitude 60° S. seems sufficient as it includes all the glaciated lands of Antarctica, and the shallower waters less than lOOOfm., connected therewith. Antarctic. Sub-Antarctic. Pycuogoimm rnagellanicuui, Hoek . .... X „ magnirostre, Mobius ...... x * Phox'cbilus australis ...... X Pallene dimorpha, Hoek ....... X * Pseudopalleiie eornigera, Mobius . .... X X ,, anstralis ..... X Pallenopsis patagonica, Hoek ....... X ,. pilosa, Hoek ... ,, fluminensis, Kroyer . . . X „ glabra, Mobius ...... X X villosa ........ X hiemalis . . Anoplodactylus neglectus, Hoek ... x ,, petiolatns, Kroyer ..... X Nymplion gracilr, Leach ..... . X „ gracilipes, Miers ...... X „ bracbyrliyuchuni, Hoek ...... X ., bamatum, Hoek . . . . fuscuin, Hoek .... . . X „ meridionale, Hoek ....... x „ antarcticum, Pfeffer ...... „ Liemale ........ x ,, lanare ......... X adareanum . . .... X ,, frigidum . . X Chretonymphon brevicaudatum. Miers .... villosiini ....... biarUeuIuttun ,, nifiidosum . . . . X „ australe, Hodgson .... „ ,, var. austrinorum * Pentanymphon antarcticum ..... Leionympbon striatum, Mobius ...... „ grande, PfetTcr gibbosum, Mobius ...... minus X Antarctic. Siib-Autarctic. LeionymphoD clansn, rfeffer. ...... x ., iiustrale . .... X glaciale spitiosuin ... . X Aminothea hoeki, Pfeft'er ...... X „ wilsoiii. Schimkewitsch ..... x „ coininuuis, Bouvier .... . x „ curculio, Bouvier ...... x Tanystylum styligcruiu, Miers ...... X dohrnii, Pfeffer ...... X chierchire, Schimkewitsch . . . . x * Austrudecus glaciale ........ x * Austroraptus polaris ....... Ascorhynctras glaber, Hoek ...... X * Rhynchothoraz uustralis ..... x Colossendeis gigas, Hoek .... . X „ leptorhynchus, Houk .... in gas leptorhynchus, Hoek . . x „ megalonyx, Hoek ...... X „ robusta, Hoek ....... X „ gracilis, Hoek ....... X ausfcralis ........ ., glacialis ........ x frigiila rugosa . . . Decolopodaf australis, Eights ... .X „ antarctica, Bonvier ...... No less than seven expeditions have taken part in the recent " Siege of the South Pole," and the collections of Pycnogonids made by four of them still remain unpublished. This being the case, it is scarcely desirable to enter into a discussion on the geographical distribution of these animals. It may, however, be stated that the head-quarters of these animals appears to be in southern seas. Professor Mb'bius (22) has compiled a list of the known Arctic and sub-Arctic species, which number forty-two. In the same work, for comparison, he has added a list of all the species taken beyond 30° South latitude. Only thirty-one species are included in this large area, and the genus Tanystylum is the only one occurring in the south which does not occur in the north. I have reduced the Southern or Antarctic area to what I consider more reasonable dimensions, and the 'Discovery' collection, with its predecessors, raises the total to sixty-three species. Among these species there are five new genera ; four of these are, as far as is yet known, confined exclusively to the Antarctic region, the other extends well into the sub- Antarctic region. The "Bipolarity Theory" is only affected by a single species, Colossendeis nnxtniUx. Of all the numerous species of this genus, C. ^/v. 4 T. V. Ho I Hi SON. to any other members of the geuus. The two species, as species are recognised no\v-a-days, are perfectly distinct, but it is a fair question to ask how is their present position at the opposite ends of the earth to be accounted for ? As to the terms employed in the following work, some words of explanation are necessary. Naturalists have not always used the same terminology, and Mr. L. J. Cole (6) has recently tabulated the essential variations. As, however, the terms used by any one naturalist have not been fully adopted, and others have been introduced, a complete account of the terminology used here is given. The entire Body of a Pycuogouid is divisible into three regions — the proboscis, trunk, and abdomen — and this without regard to any of the appendages. Where the body only is alluded to, it is to be understood that both the trunk and abdomen are taken together. Measurements are taken dorsally, unless otherwise specified, except in the case of the appendages, which are generally measured from the side, and the length of the trunk is usually taken to the base of the abdomen ; in exceptional cases, where the abdomen is vertical or very short, the trunk may be measured to the extremity of the posterior lateral processes, but this is so stated. Its width is always across the longest of the lateral processes. The C'ephalon is regarded as that portion of the trunk which lies in front of the first pair of lateral processes, and the so-called neck is the narrowest part, sometimes elongated, between those processes and the more expanded distal portion. Segmentation is not regarded as perfect or complete unless the four segments of the trunk and the abdomen are distinctly articulated. The first appendage of the trunk is the Cheliforus, also commonly known as the mandible. A considerable amount of confusion has been, and is still likely to be, caused by the fact that the chela has most frequently been regarded as a single joint. Obviously it consists morphologically of two joints, and in order to avoid any misapprehension as to the number of joints, this appendage has been described as chelate, or otherwise, and the scape, a name given by Professor G. 0. Sars to the shaft supporting the chela, has been recorded as one- or two-jointed, as the case might lie. This method of dealing with the limb is suggested in order to avoid confusion as to the number of joints it possesses. The second appendage is the Palp. The third appendage is the Oviger. This convenient name was given by Mr. L. J. Cole to replace the more cumbrous term " ovigerous," or " false leg." In these two appendages the various joints are numbered from the base, and not named. The remaining four or five pairs of appendages are Legs pure and simple ; with the use of the word " oviger," the qualification " ambulatory " or " walking leg " becomes quite unnecessary. The terms used for the individual joints are those adopted by Professor G. O. Sars, viz., first, second and third coxa, femur, first and second tibia, tarsus and propodus. PTCNOGONIDA. 5 A projection lioyond the insertion n!' Ilic terminal claw, which occurs in some speck's, is called the Heel, a term introduced by Mr. L .1. Cole. Two oilier expressions have been adopted for purposes of convenience. In MT\ many species, not to say genera, then- occurs a thickening of the skin on the Miles of the logs, not inrro<|uently also on some of the other appendages ; this takes the form of a narrow ami conspicuous line, usually of a reddish colour, and so it has been termed the "lateral line." The other feature concerns the setae. At the extremity of most of the joints there is a fringe of more or less specialised setae, sometimes surrounding the joint, bin frequently more conspicuous on the dorsal or the ventral aspect. This has been termed the distal fringe, a name which does not appear to be inappropriate. Precise measurements are invariably necessary with regard to the legs. One leg is generally considered to be sufficient for this purpose, and as Dr. P. P. C. Hoek adopted the third leg of the right side for this purpose wherever possible, the same limb has been used here. PHOXICHILUS. This genus is readily distinguished by its slender form and the complete absence of chelifori and palps. The ovigers too only occur in the male, and are seven-jointed. Among other characters may be mentioned the presence of a " collar " between the cephalon and the proboscis. This, however, is deficient in the species described below. Numerous species have been assigned to this genus, but the difficulties of species discrimination is increased by the absence of two of the normal number of appendages, and necessitates some modification of the generic characters. No less than six species have been described from European seas, but their specific distinctness is open to question. Three others have been found in distant seas, and a fourth now described is from the extreme south. PHOXICHILUS ADSTRALIS. (Plate I, fig. 1.) Specific characters : — Body slender, with lateral processes very widrly separated and with the long legs completely covered with very minute still' si-be. Tarsus with a very prominent ventral spine, and three to five proximally mi ilie propodus, which projects distinctly beyond the insertion of the terminal claw and auxiliaries. X<> distinct collar anteriorly to cephalon. Body slender, with the lateral processes long and very widely separated ; perfectly smooth to unassisted vision, but with a 1-in. objective extremely minute spines can be detected; segmentation very prominent and immediately behind each pair of lateral processes. The Cephalou is small, but stouter than the trunk, truncated anteriorly with the angles bevelled off. No collar exists as such, but a band of thin chitinous skin, characteristic of an articulation, occurs between the cephalon and the base of the proboscis. r> T. v. HODGSON. The Ocular tubercle lies almost in the middle of the cephalon, but scarcely dear of the first pair of lateral processes. It is very stout, of no great elevation, terminating in a strong cone above the four eyes. The Abdomen is small, cylindrical, terminating in a cone, and directed almost vertically upwards. It is not articulated to the trunk. The length of the trunk is 5mm. (to extremity of posterior lateral processes) and its extreme width is 3 mm. The Proboscis is long and slender, scarcely 4mm. in length, flexibly united to the trunk. It is cylindrical, but very slightly swollen before the middle and equally slightly narrowed before its rounded extremity. The mouth is inconspicuous, but of normal size. The proboscis is covered, more especially distally, with extremely minute spines. The Legs are long and slender, attaining a length of 30mm. The first coxa is the smallest, and the second is a trifle longer than the first and third together ; the pro- portions of the three following joints are as 8 : 675 : 8'5 ; the tarsus is very small, and the propodus, which is curved, is about a quarter the length of the femur. The entire limb, as the trunk, is completely clothed with extremely minute stiff setai, which for the most part are only visible with a powerful lens. On the tibia they are, however, rather more conspicuous, besides being most abundant. The larger or ventral surface of the tarsus is covered with short spines, but one distal one is extremely large and prominent, Dorsally the propodus is covered with the minute stiff' setae, ventrally there are at the proximal end of the joint three to five very large spines, the remainder of that surface being occupied by a band of much smaller though still conspicuous spines of rather irregular size. A prominent heel projects over the insertion of a powerful terminal claw and its two auxiliaries, these latter being about half its length, but much more slender. The second coxa bears dorsally, just beyond the middle of its length, a tubercular enlargement, which is perforated by a glandular opening. The genital apertures occur on a transverse ridge at the extremity of the second coxa of every leg. Veutrally, in the angle formed by the first pair of lateral processes and the trunk, there is a very small but distinct process on each side, exactly in the position where the oviger should be. This type specimen is a female, and was taken off Flagon Point in Winter Quarters in 5-20 fm., on very rough ground. Two other females were taken, one slightly larger than the type came from 125 fm., on a bottom composed of small stones and organic debris; the other is much smaller, but the precise point at which it was captured in Winter Quarters remains uncertain. A fourth specimen is a male, and is to a considerable extent overgrown with polyzoa. This specimen was taken at the same time and place as the type. It is sexually mature, and the genital apertures occur on the three posterior legs only. The ovigcrs are well-developed, but unfortunately only four basal joints remain on either side. They arise in the angle formed by the first lateral process and the trunk, PYCNOGONIDA. 7 luit not on a body process ; the first joint is small, the second is a little longer, the two following which are longer still, the fourth is largest. The appendage bears a moderate number of minute setje. I have been unable to distinguish the cement glands on the femur as described and figured by Professor G. H. Carpenter for other species. (4 and 5.) PSEUDOPALLENE. This genus, established by Mr. E. B. Wilson in 1878, has been more completely defined in accordance with modern requirements by Professor G. 0. Sars (25). It is very closely allied to Cordylochele (G. 0. Sars), but the special features which distinguish it from that genus are (i<'fi of Professor Bouvier. Though I have seen both species, I must admit that I have not examined them with that care that the fact of a second closely allied species having been found demands. The essential difference between the ' Discovery ' and the 'Valdivia' spednieiis occurs in the length of the legs, which are half as long again in the latter specimens. N 2 10 T. V. HODGSON. PSEUDOPALLENE AUSTRALIS. (Plate I, fig. 2.) Specific characters : — Body with lateral processes widely separated, these and the cephalon armed with stout spurs. Limbs armed with rows of prominent tubercles which bear the sets. Propodus with few setee dorsally and a proximal group of three or thereabouts. Oviger ten-jointed, four terminal joints long and cylindrical. Denticulate spines without lateral teeth at base. Body rather robust, though more slender than in the last-named species ; lateral processes widely separated, and but little longer than the trunk is broad. It is smooth except for the spurs on the cephalon and lateral processes. These are similar to but more upright than those of P. cornigera. The segmentation is distinct. The Ocular tubercle is short, stout, rounded at the extremity, and bears four large well-developed eyes. It rises just clear of the first pair of lateral processes. The Abdomen is of normal proportions, rather ovoid in shape and without setae. There is no articulation, and it is directed obliquely upwards. The length of the body is Gmni. and its extreme width is 3mm. The Proboscis and the Chelifori are as in the preceding species. The Ovigers (fig. 2 a) rise just behind the neck, each from a small body-process. The first joint is very small and stout, the second equally stout, but much longer ; the third is more slender, and has the usual oblique termination, but is scarcely as long as the two preceding joints ; the fourth is nearly as long as the three preceding. The fifth is much the longest of the appendage, slender and rather enlarged distally. The sixth is quite small, about a quarter the length of the fifth. All these joints bear a very few minute setae, all of which have traces of an enlarged base. The four terminal joints are long and slender, with very little difference in their length ; the first is longest, the next two are subequal, and the last the shortest. All are provided with numerous denticulate spines, which occur in a single row (fig. 2 b). They comprise a rather conical shaft, surrounded by a flat leaf-like blade with a finely dentate margin. There is no trace of the stout basal teeth so characteristic of the preceding species. The end of the terminal joint bears two curved spines, which are obviously the same denticulate spines worn down. The character of these four terminal joints differs from those of the preceding species in their more slender and cylindrical form as well as their greater length. The Legs extend to a length of 23mm. Of the three coxae the second is quite as long as the other two together ; the proportions of the three following joints are as G : 5'5 : 5'5 ; the tarsus is very small, the propodus is curved, especially proximally, and rather more than one-third the length of the second tibia. The terminal claw is very long and slender ; there are no auxiliaries, nor is there any heel. The setaj, if such they may be called, are small and delicate. They lie in lines parallel to the surface of the joint, and, with very few exceptions, each one occurs on a prominent I'VCXOCOXIDA. 11 tubercular process arched towards the extremity of the limb. They occur distally on the first coxa, dorsally on the second, where there are two rows, and ventrally on the third coxa. Elsewhere there are five rows in which the ventral tubercles are the smallest. Between the two rows on the second coxa distally is a rounded tubercle bearing no seta. The distal extremity of the second tibia is liberally provided with small stout setfe not connected with tubercles ; its distal fringe is inconspicuous. The tarsus is covered with setae which increase in length distally, forming a fringe of long and stout seta;. The tubercular character of the leg completely disappears on this and the succeeding joint. ( hi the propodus there is a scanty supply of minute setae dorsally, and ventrally at the proximal end of the joint is a well-developed enlargement bearing three spines of moderate strength ; the rest of the ventral surface is occupied by a band of small but fairly prominent spiuous setae. A single specimen of this species was taken off the Barrier, lat. 78° 25' 40" S., long. 185° 39' 6" E. in SOOfms. Bottom, mud. It is an adult female, with the Genital apertures prominent on the second coxae of all the legs. PALLENOPSIS. Body slender or robust, distinctly segmented. Proboscis cylindrical, ventral in origin, flexibly united to the trunk. Abdomen long and slender. Chelifori well developed ; scape long, two-jointed. Palps reduced to a more or less conspicuous knob. Ovigers ten-jointed, present in both sexes, without a terminal claw or denticulate spines. Legs with auxiliary claws. A tubular duct occurs in a mid-ventral position on the femora of the male. Ocular tubercle placed anteriorly on the cephalon, with two unequal pairs of eyes. As above stated, the generic definition is much altered from the original of Prof. E. B. AVilson (32). Besides the two new species described below, no less than thirteen have from time to time been recorded, all of them from a strictly limited number of specimens. They arc separated by characters which, when committed to paper, do not appear as definite as one would like. Nothing is known with regard to the variation which may occur within the limits of " a species," and so it must remain open to question whether I have taken the right course with reference to P. hiemalis and P. pilosa, Hoek, or not. PALLENOPSIS GLABRA. Pallenopsis glabra, Mobius (23), p. 1«4. Specific characters : — Body comparatively slender, with lateral processes widely separated, and with two small tubercles dorsally. Chelifori well developed, scape two-jointed, the whole limb minutely scabrous. Palps reduced to a conspicuous stump. Ovigers ten-jointed, without claw or denticulate spines. Legs long, covered throughout with minute spiuous setae. 12 T. V. HODGSON. I am unable to find any satisfactory grounds for separating this species from that of Professor Mobius. A full description follows, as that of Professor Mobius is scarcely sufficient on small points. Body comparatively slender, with the lateral processes widely separated and slightly increasing in length to the third, which is directed back- wards. The Cephalon is long, rather broader than the rest of the body, bevelled anteriorly to form a median point, immediately behind which lies the stout ocular tubercle. This is stout, erect, rounded in front, and terminating in a short spine on the posterior half of the tubercle above the eyes. The four eyes are well developed, the anterior pair being much the larger. The Ovigers arise on small body-processes immediately in front, and rather below the level of the first lateral pair. The Abdomen is very long, slightly curved, and with a clavate extremity ; it is not articulated to the trunk, and is directed obliquely upwards at a considerable angle. It is covered with minute curved spines. The segmentation of the trunk is rendered conspicuous by a slightly raised ridge forming the posterior border of the segment, these ridges are rather more prominent ventrally, and in both cases bear a few minute spines. Similar spines occur on the lateral processes, and form a distal fringe round them. The Proboscis is movably articulated to the trunk and directed downwards, its origin is ventral, and at the proximal end of the cephalon ; it is cylindrical, tapering slightly, its distal extremity rounded and the mouth small. It is completely covered with minute spines except for a narrow band in the mid-ventral line. The Chelifori are well developed, and arise close to the middle line, their origin occupying almost the entire width of the cephalon. The scape is two-jointed, and half as long as the trunk measured to the base of 'the abdomen ; the two joints are sub-equal in length, the second being expanded distally. The chela is directed downwards, the palm rather curved, and fully as long as the other joints. The small dactyli are directed inwards, the movable one having a spinous cushion at the base. The entire appendage is covered with minute spines, largest and most numerous on the second joint of the scape, the distal fringe of which is also more conspicuous. The Palps arc stout single-jointed stumps arising from the sides of the cephalou, .•ibout the middle of its length. The Oviger is ten-jointed. The first joint is very short and stout, the second is much longer, clavate and setose on its outer margin ; the third is shorter, curved, and having a very oblique termination ; it is also setose on its outer margin. These three joints form a curve in one direction, and the following three curve in another. The fourth and fifth joints are comparatively long and sub-equal, both slightly curved, the fourth setose on both sides, the fifth only on its outer margin ; the sixth joint is short and much curved, and from this one the remaining joints become shorter, more slender, and more setose, the setas being longer than elsewhere. There is no terminal claw, nor denticulate spines. PYCXOGONIDA. 13 The Legs are long, attaining a length of 69mm. The lateral line is conspicuous, beginning on the lateral processes and extending to the end of the second tibia. Of the three coxae the second is longer than the other two together, all three are thickly covered with small spinous setae on the ventral surface, but, except on the first coxa, there are none dorsally. The proportions of the three following joints are as 17 : 14 -5 : 21. The femur is fairly well covered with minute setas ventrally ; dorsally they are much less numerous, except at the distal extremity. A linear arrangement of the setae is observable, but it is not very regular, a distal fringe is not very prominent, and almost confined to the dorsal side. On the first tibia the setae become more numerous dorsally, they preserve the same general arrangement, but there are longer setae mixed with them. On the second tibia this becomes much more pronounced, and veutrally the setae are so numerous that the linear arrangement is completely obscured ; the distal fringe on both joints is well developed, more especially so on the ventral side of the second tibia. The tarsus is very small, the ventral surface being double that of the dorsal ; the former is covered with long spinous setae, most prominent distally, like those of the distal fringe of the preceding joint, dorsally they are smaller, but form a well-developed fringe. The propodus is slightly curved, and completely covered with small spinous setae, and some of these form a distal fringe over the insertion of the terminal claw and its auxiliaries. At the proximal end of the joint is a series of some half-dozen short spines, the centre ones being the largest ; beyond these a group of stout spiuous setae extends to the end of the joint. The terminal claw is short, half the length of the propodus, and the auxiliaries are about half its size. Of the two specimens obtained one is a male, and the Genital apertures occur on a slight swelling at the distal extremity of the second coxae of the two posterior pairs of legs. On the ventral surface of the femur is a swelling about the middle of its length, and this bears a short but stout duct characteristic of the males of this genus. The Genital apertures of the female occur on a very pronounced swelling, in a similar position to those of the male, but on all the legs. This specimen is remarkable for having the first leg of the right side complete in all essential details, but not extending beyond the distal extremity of the femur of the normal limb. Winter Quarters, off Flagon Point. January 17th, 1903. 5-20 fm. Very rough ground. PALLENOPSI* VILLOSA. (Plate II., fig. 1.) Body robust, with lateral processes rather close together. Entire animal clothed with long, slender settv, giving it a woolly appearance. Chelifori well developed, scape two-jointed, no setous cushion at the base of the dactylus. Palps reduced to a knob. Oviger ten-jointed, without claw or denticulate spines. Legs densely clothed with fine sette, propodus \\ith several strong spines ventrally ; one or two of the proximal ones air- much the largest. 14 T. V. HODGSON. Body robust, with the lateral processes distinctly, but not widely separated. Segmentation is complete, and in the case of the trunk it is rendered very prominent by each segment to some extent overlapping the following one ; this is most noticeable ventrally." The Cephalon is large, with a distinctly constricted neck. At its extreme anterior end, which is straight, the stout rod-like ocular tubercle projects slightly forwards ; this is rounded at its extremity, where there are four well-developed eyes, the anterior pair very much larger than the posterior. The Abdomen is long and distinctly articulated to the trunk ; it increases in diameter to a short distance from its extremity, when it abruptly tapers to a blunt point. About its middle it is provided with a considerable number of long slender setas. Similar setae fringe the anterior border of the cephalon, the distal extremities of the lateral processes, and the posterior border of each segment. None of these setae are present ventrally. The length of the body is 10mm., and its width is 6' 5mm. The abdomen measures barely 4mm. The Proboscis is stout, cylindrical, rounded at the extremity, and articulated to the trunk on the ventral surface, and therefore directed downwards. The mouth is small. It is liberally covered with short setae. In length it is scarcely half that of the body. The Chelifori are long and chelate ; they arise quite close to the middle line underneath the anterior border of the cephalou. The scape is stout and two-jointed, measuring some 5mm. in length ; the two joints are sub-equal and covered with long slender setae, the second joint more abundantly so, especially distally. These setae are confined to the dorsal surface ; a row exists ventro-laterally, but veutrally they are replaced by very short setae. The third joint, forming the chela, is directed down- wards, and is shorter than the preceding. It is covered all over with setae, shorter than the average, but varying in length from the proximal to the distal end ; on the outside of the movable finger is a dense tuft of long setae (fig. la). The dactyli are turned inwards, the movable one being the longer. They are curved at the tips, which cross over each other, and are devoid of teeth. The Palps arise at the side of the proboscis, and are nothing more than rounded knobs. The Ovigers are ten-jointed, and without terminal claw or denticulate spines (fig. Ib). They arise ventro-laterally between the base of the proboscis and the first lateral processes. All the joints are small, and the appendage is curved like an attenuated S, and setose throughout. The first joint is small and stout, the remainder gradually decrease in breadth ; the second is about twice as long as the first ; the third is intermediate between the two, and has a very oblique termination. These three joints bear long setae on the outside of the curve formed by them. The fourth joint is the longest on the appendage, and slightly curved ; it bears a few long setce on the inner side, and numerous short ones on both. The fifth joint is not so long, also slightly curved and dilated distally with long setae on its outer side. The sixth joint is shorter and slightly curved ; it is thickly clothed with long setae, and bears a few PYCNOGONIDA. 15 on the opposite side distal ly. The seventh, eighth, and tenth joints are sub-equal in length, and the ninth is a little shorter. The arrangement of the setae is the same as on the sixth joint, except that the distal group on the outer side increases on each joint, so as to involve the whole of it. The setae on the five terminal joints are very long and quite simple. The Legs are very stout, and some 36mm. in length. The first coxae are about as long as their corresponding lateral processes ; the second are longer, and, in the female, bear a conspicuous enlargement ventrally near the distal extremity, upon which the large genital openings occur ; these are on all the limbs. The third coxae are about the same size as the first. The three following joints differ but little in size, being proportionally as 8'5 : 9 : 9'5. The tarsus is very small, and the propodus is about a quarter the length of the second tibia. The entire limit is clothed with setae. Dorsally the three coxae each bear a prominent distal fringe of long setae. The first has two lateral bands in addition, while the other two are more completely clothed. Ventrally the third coxa is partially covered with small setaa, and has a prominent distal fringe of longer ones, the other two only possess a distal fringe of short setae. On the femur the dorsal surface is covered with long setae, which also form a prominent distal fringe ; the ventral surface bears only small setae, but on each side there is a band of the large ones just below the well-developed lateral line. This arrangement holds good on the two tibiae, but the setae are much more thickly set. At the distal extremity of the second tibia the setae become spiuous ventrally, and as spines form the distal fringe on that side. The ventral surface of the tarsus is clothed with spines which are large distally ; dorsally there is a fringe of setae only. The propodus is covered dorsally with setae of more moderate length than those on the appendage generally ; laterally they are smaller still, and along the ventral aspect there is a row of about a dozen strong spines, a little irregular in size, but one or two of the proximal ones are much the largest. There is no projection of the propodus beyond the insertion of the terminal claw, which is stout and rather more than half the length of the joint that bears it. It is accompanied by two small auxiliaries. The single specimen is an adult female, and contains ripe ova. Taken off Coulman Island in 100 fm., on mud and stones, January 13th, 1902. PALLEXOPSIS PILOSA. (Plate II., fig. 2.) Pkoxichilidium pilosum, Hoek (14). p. 90. Pallenopsis pUosa, Hoek (Ifi). p. l>. Specific characters :— Body not very robust, with lateral processes not widely but distinctly separated. Body (dorsally) ;iml legs covered with extremely lon^ thin hairs. Chelifori well developed, scape showing distinct articulation on the dorsal surface. No setose pad at base of dactylus. VOL. in. O 1G T. V. HODGSON. Body fairly robust, with lateral processes distinctly, but not widely, separated ; two pairs directed forwards and the other two backwards. Cephalon stout, longer than two segments of the trunk, cylindrical, with its anterior border bevelled on each side ; near the point thus produced lies the Ocular tubercle. This is short and stout, capped by a blunt point below which are four well- developed eyes ; the anterior pair larger than the posterior pair. The Abdomen is long and slender, terminating in a blunt point, and bearing numerous long setae. The segmentation of the body is perfect, and on the posterior margin of the three anterior segments are two tufts of long slender setae, a number of which occur also on the lateral processes, and also form the distal fringe. The ventral surface is devoid of setae. The length of the body is 10mm., its width 5mm. The abdomen measures 4mm. in length. The Proboscis is ventral in position, directed downwards and movably articulated to the trunk. It is cylindrical, terminating in a blunt cone ; mouth small, covered with small setae 4mm. long. The Chelifori are well developed ; they arise close to the middle line in front of the cephalon, and extend considerably beyond the proboscis. The scape is long and single- jointed, though dorsally there is a slight enlargement about the middle of its length, indicating a possibly fused joint. Numerous long and slender setae are distributed over the scape. Distally the setae are smaller, and there is a strongly developed distal fringe. The chelae are comparatively small, and hang vertically. The palm is scarcely more than a quarter the length of the scape, covered with short stiff setas. The fingers are small, and directed inwards at a considerable angle from the palms ; the movable finger is nearly twice the size of the other, but neither bears any trace of teeth. The Palps are quite rudimentary, being nothing more than a small but conspicuous rounded stump at the side of the proboscis, well behind the ocular tubercle when viewed from the dorsal aspect. They bear a few small setse. The Ovigers occupy a lateral position immediately in front of a shallow groove separating the cephalon from the first lateral processes. They are ten-jointed (fig. 2). The first joint is small and stout ; the second is about three times as long, enlarged distally ; the third is intermediate in length between these two ; the fourth is long, about as long as the two preceding joints, and very stout ; the fifth is very little longer, slightly narrowed in the centre, and expanded distally ; the sixth is stout, and not half the length of the fifth. All these joints bear a few short setae, most numerous on the outer side of the fifth and sixth joints. The seventh joint is longer than the sixth or the two following together ; of these the proximal is shorter, the terminal joint (missing in the appendage examined in detail) is quite small and without a terminal claw. The last four joints bear long and stout setie of a simple character. There are no denticulate spines, PYCNOGONIDA. 17 The Leg attains a length of 32mm. Of the three coxae the second is about as long as the other two together, and is much enlarged distally. The first bears a mid-dorsal row of a few long seta) and a distal fringe of the same kind. The second bears two dorso-lateral rows and t lie distal fringe ; and ventrally, a conspicuous fringe between the distal extremity and the genital apertures. The third coxa is covered ventrally and laterally with setae and carries ventrally a very prominent distal fringe. The proportions of the three following joints are 8 '5 : 8 '5 : 10, these joints are covered with lines of very long slender setae, their great length making it difficult to determine the precise number of rows. On the femur they are most abundant ventrally, except near the distal extremity. On the two tibiae the ventral surface is much more scantily supplied. The distal fringe of the second tibia is rather spinous ventrally. The tarsus is very small, setose, and with a few spinous setae at its ventral extremity. The propodus is curved, covered with rather short setse, a fringe of longer ones distally ; there is no heel. Ventrally at the proximal end of the joint are two or three stout spines, and a baud of smaller ones of irregular size extends to the end of the joint. The terminal claw is long and slender, with two well-developed bub not large auxiliaries. Small setae also occur more or less abundantly throughout the limb. The Genital apertures of the female occur on the enlarged part of the second coxa of every leg. In the male these orifices occur at the apex of a pointed tubercle on the two posterior legs only. The male as a rule is more setose than the female, and on the mid-ventral surface of the femur there is the duct so characteristic of the males of this genus ; in this species it is long and slightly twisted, conspicuous even among the long setae. The joints of the ovigers up to the sixth joint are more strongly developed, longer, and all are more setose than those of the female. One specimen has three perfect ovigers, two on one side being in contact with one another. The eggs are rather large, and held round each oviger in a single rounded mass. Several specimens of this species were taken off the Ice Barrier in the Eoss Sea, 300fm., mud bottom. I am unable to find any satisfactory reason for separating them from the species of Dr. P. P. C. Hoek. They are smaller, and the only character which can be used to separate them is the comparative length of the four terminal joints of the oviger, but this does not seem to me to be sufficient. PALLENOPSIS HIEMALIS. (Plate I., fig. 4; Plate II., fig. 3.) Body well built, with lateral processes widely separated, but of variable length, and having a tubercular swelling at the dorsal extremity. Chelifori and abdomen both proportionally long. Palps, a rather long stump. Legs clothed with short, stiff sette. Body well built, with the lateral processes rather widely separated, as long as the trunk is broad, and each bearing distally a stout tubercle of no great elevation. o 2 18 T. V. HODGSON. The Cephalon is elongated, but not much enlarged in diameter, with a very slightly constricted neck between the first pair of lateral processes and the small body-processes from which the ovigers arise, and which are plainly visible dorsally. The anterior margin of the cephalon is angular, and the Ocular tubercle arises at its front. This is stout, directed very slightly forwards, and terminates in a point above the four well-developed eyes ; the anterior pair are larger than the posterior. The Abdomen is long, not articulated to the trunk, and slightly enlarged before it terminates in a blunt point ; it is directed upwards to a moderate extent. The length of the body is llmm., its width 4'75mm., and the length of the abdomen is 375mm. A few small, stiff setae occur dorsally at the posterior margin of the segments and at the extremity of the lateral processes. The Proboscis is stout, cylindrical, rounded at the extremity ; the mouth is small. Ventrally it measures 4mm. in length and, except in the mid-ventral line, it is closely covered with small, stiff setse. It is ventral in position, directed obliquely downwards, and articulated to the trunk. The Chelifori are well developed, and arise close together above and in front of the proboscis. The scape is long and stout, projecting beyond the extremity of the proboscis, though only 4mm. long. It is divided by a distinct joint into two sub-equal portions and covered completely with short, stiff setae ; the second joint is expanded distally and has an oblique termination. The chela is well developed, the palm being rather shorter than the joints of the scape, but like them densely setose. The dactyli are set on its inner extremity and lie transversely. They are short and stout, smooth without teeth ; the movable one is the larger, and has a setose pad at the base. The Palps are stout, single-jointed, rather long stumps ; they arise from the sides of the cephalon about the middle of its length. The Ovigers are ten-jointed, without terminal claw or denticulate spines (fig. 4a). The appendage arises on a small process of the body in front of the first lateral process. The first joint is short and very stout ; the second is at least twice as long, slender proximally, much dilated distally ; the third is shorter, and the oblique articulation of this joint with the next renders the fourth to all intents and purposes lateral ; the fourth is the longest of the appendage and stout ; the fifth shorter, and the sixth shorter still. The limb is curved in the form of an S, the first three joints forming the curve in one direction, the three following curve in another. Of the four terminal joints the seventh is short, the eighth is longer, the ninth and tenth progressively shorten. The entire appendage is setose, the setae are small and rather sparse proximally, becoming more numerous to the fifth joint ; from that joint onward they are longer, but quite simple, and more completely clothe the joints. The Legs extend to about 38mm. Of the three coxse the second is fully twice as long as the other two together, and bears a low rounded tubercle dorsally, just beyond the middle of its length. The first coxa carries dorsally a stout hut short tubercular process, similar to, but smaller than, that of the lateral process. The proportions of PYCNOGONIDA. 19 the three following joints are 9 : 8'5 : 11 '5. The tarsus is very small, and of the normal shape. The propodus is one-third the length of the femur, very slightly curved. At the ventral side of the extremity is a stout claw, with two well-developed auxiliaries ; the heel does not project beyond the insertion of these claws. The joint is uniformly clothed with short spinous setae, and there is dorsally a projecting fringe. Ventrally there is a row of stout spines, of which some half-dozen, not very regular in their position, are very prominent (fig. 3). The entire limb is uniformly and densely clothed with very short, stiff setae, and these, as is usually the case, are more numerous and longer on the second tibia ; the distal fringe on this latter joint is prominent, with at least one stout spine ventrally. The ventral setae on the tarsus are also spinous, one being particularly large. The lateral line is very prominent from the lateral processes to the tarsus, both inclusive. The specimen is a female and bears Genital apertures on a swelling of the second coxa of every leg. Winter Quarters, inside the 20-fm. line. A specimen was taken off Cape Wadworth, Coulmau Island, which, notwithstanding certain important differences, I cannot regard as being specifically distinct. It is a male, and rather larger thcin the type. The obvious differences lie in the much greater length of the lateral processes and the character of the ventral spines on the propodus (fig. 3a). With regard to the first of these features, the third lateral process of the right side is but little more than half the length of the others ; the first coxa, the only joint of that appendage that exists, is also abnormally small, though there are no definite traces of injury. The other feature rests on the armature of the propodus. The ventral surface of this joint bears proximally three very stout spines, and from there to the extremity is a band of spinous setae. The length of the body is 12mm., of the trunk only 9mm., and its extreme width is (>mm., rather larger, especially in the last measurement, than the type. The chelifori (scape) and the abdomen are a little shorter. The oviger differs only in being much stronger ; the setae are more numerous and also stronger. The fifth joint is however longer, nearly equalling the fourth. This is a not uncommon sexual difference. The lateral processes and the first coxa exhibit in a less degree the tubercular processes of the type. The proportions of the three principal joints of the legs are 975 : 8 '5, and 12, a difference of no importance. These limbs are setose throughout, though the setae are rather deficient proximally, becoming much more abundant on the tibia. Ventrally they are very small, stiff, and crowded ; dorsally much less numerous. They have among them a number of much longer and more slender setae. The tarsus is coarsely setose ventrally, with one very prominent spine. The distal fringes of the joints are not strongly developed ; that of the second tibia is chiefly ventral and spinous. The lateral line is very distinct from the lateral process to the end of the second tibia. The femur is swollen ventrally near the middle, and bears a very short but stout tubular duct, 20 T. V. HODGSON. Another specimen, a male, was taken in Winter Quarters, inside the 20-fm. line before the ship was frozen in. It is in a severely mutilated condition, having lost the posterior segment of the trunk and several legs. It differs slightly from the male above described, the lateral processes being a little closer together and the body, especially the cephalic portion, being a trifle stouter, and the tubercular knobs on the lateral processes not being so distinct, but all these features can, I think, be readily accounted for by age. This species is closely allied to P. patagonica, Hoek. NYMPHON. This genus is perhaps the most widely distributed and best known of all the genera of Pycnogonida. It is readily distinguished from all others by the well- developed chelifori, the five-jointed palps, and the ten-jointed ovigers, the four terminal joints of these being provided with a single row of denticulate spines. The form of the body varies greatly within certain limits, and Professor Sars (25) has subdivided the genus into three :— Nymphon retains the more slender and comparatively long-legged species. Chsetonymphon the more robust and short-legged species, which also, as a rule, are more setose on the body than those of the original genus, Nymphon, Boreonymphon, another robust form, readily separable from the others by the absence of teeth on the chelae, the spines of the ovigers being simple and not denticulate. The species brought back by the ' Discovery ' are eight in number ; four are assigned to the original genus, though one of these, N. adareanum, bears a few simple spines on the oviger instead of the rows of denticulate spines. The other four, of which one, for the present at least, is regarded as a southern variety of a previously described species, are assigned to the genus Clisetonymphon. NYMPHON HIEMALE. (Plate III., fig. 1 ; Plate X., fig. 8.) Specific characters :— Body slender, with rather long lateral processes very widely separated. Limbs covered with very minute setre. Ocular tubercle stout and short. Pulps five-jointed, proportions of last three as 7 : 4 : 5'5. Oviger ten-jointed, denticulate spines rather numerous, with eight to ten teeth on each side. Legs long, scabrous, terminal claw with well-developed auxiliaries. Body smooth, slender, with rather long lateral processes, which are very widely separated ; the first of these is curved forwards. The segments are very strongly marked immediately behind the lateral processes. The Cephalon is long, the greater part of its length is taken up by a slender PYCXOGONIDA. 21 neck ; anteriorly it is much expanded, the two lobes being separated by a small but conspicuous groove. The Ocular tubercle is situated immediately in front of the first lateral processes ; it is comparatively stout, short, truncate, and bears four well-developed eyes without any pigment. The Abdomen is small, ovoid, does not project beyond the last pair of lateral processes, and is not articulated to the trunk. The length of the body is 7 '5mm. and its width is almost 4mm. The Proboscis is cylindrical, smooth, and directed obliquely downwards ; it is about 3mm. in length. The Chelifori are well developed. The scape is as long as the proboscis, slightly curved and sparsely covered with minute setae ; the distal fringe is not conspicuous. The chelae are also curved, half their length being taken up by the palm, which is finely setose, the setae extending on to the base of the immovable finger. The fingers are slender, much incurved at the tip. The teeth are numerous and regular in size, not so closely set in the immovable finger as in the other. The Palp is slender, five-jointed, and rises at the side of the proboscis below the chelifori (fig. la). The first joint, as usual, is very small ; the second is the longest of the appendage, slightly swollen distally, and sparingly covered with minute set*. The third joint is but a little shorter, rather stouter, and more liberally supplied with short setae, though these are still scanty. The fourth joint is scarcely half as long as the second, very richly supplied with short setas on its ventral margin, much more sparingly dorsally. These three joints have a well-defined distal fringe. The terminal joint is nearly half as long again as the preceding and, like it, richly clothed with short setae ventrally, more sparingly dorsally. The Oviger is ten-jointed, and arises ventro-laterally in front of the first lateral process on a prominent body-process, the position of which is clearly seen from the dorsal surface (fig. lb). The first three joints are small and stout, the third curved and having a very oblique termination ; only a distal fringe of very small setae can be detected on these joints. The fourth joint is very long, slightly curved, with very few minute set* besides the distal fringe. The fifth joint is much the longest of the appendage, and is thinly covered with very small setas, with a more strongly marked distal fringe. The sixth joint is little more than half as long as the preceding, slightly curved, and thickly clothed with small stiff setae on its outer side and a well-developed distal fringe. The four terminal joints are long, progressively decreasing in length, but the last two are sub-equal. All are more or less well supplied with short stiff setae dorsally and a distal fringe of rather longer setae. The terminal claw is long and slender, with about fourteen curved teeth. The denticulate spines are long, and in the specimen critically examined occur 13:10: 10:9 on the various joints. (Plate X., fig. 8.) The shaft is flattened and slender, and carries eight to ten teeth on each side ; the third or fourth T. V. HODGSON. from the base is the largest, the remainder tapering off to very minute proportions. The eggs are small and the spherical mass is packed round the proximal part of the fifth joint. The Legs are long and slender and attain a length of about 45mm. The second leg of the right side has in this case been selected for measurement. Of the coxse the first and third are sub-equal, the second being quite as long as the other two together. The proportions of the three following joints are as 10 : 11 : 16, and the tarsus and propodus taken together are 4'5, the former joint being a little the longer of the two. A lateral line is plainly visible on the femur and to the end of the leg. On the femur such setae as exist are extremely minute ; on the second tibia they are very numerous but small, arranged principally dorsally and ventrally, with a distinct distal fringe. On the tarsus and propodus the arrangement is the same, but the setse are even more crowded. Ventrally on the propodus is a row of about a dozen comparatively strong spines, more distally than proximally. There is a distinct heel fringed with rather long setse. The terminal claw is stout and accompanied by two auxiliaries about one-third its size. The Genital apertures of the male are found on the second coxte of the two posterior legs, those of the female being found on all the legs. A number of specimens were taken in Winter Quarters in 125 fm. NYMPHON LANARK. (Plate III., fig. 2; Plate X., fig. 9.) Specific characters : — Body very slender, with lateral processes long and widely separated. Ocular tubercle short and stout. Palps five-jointed, proportions of last three 10 : 0 -.11. Oviger ten-jointed, denticulate spines, about double the number on the first joint as on any of the others, with five to seven teeth on each side. Legs long and slender, with long and fine sets, terminal claw long, without auxiliaries. Body very slender, with lateral processes long and very widely separated. The Cephalon is long, expanded anteriorly into two lobes separated by a narrow groove. The neck is elongated, and at its base, ventrally, are small body-processes for the attachment of the ovigers, visible from the dorsal aspect. The Ocular tubercle is short, stout, and truncated ; it lies immediately in front, but not quite clear of the first pair of lateral processes. It bears four well-developed eyes. The Abdomen is quite small, and does not extend as far as the posterior lateral processes. It is directed slightly upwards, and not articulated to the trunk. The length of the body is 8'5mm., and its width 5mm. The Proboscis is cylindrical, slightly swollen in the middle, its extremity being rather angular. Together with the body, it is quite devoid of setse. The Chelifori are well developed, long and slender. The scape is single-jointed, longer than the proboscis, but scarcely as long as the chela. It bears but few setse, PYCNOGONIDA. 23 except a distal fringe of long and slender ones. The palm of the chela occupies about half its length, and bears a number of fine setae dorsally. The fingers are long, slender, incurved at the tips, and provided with numerous slender teeth, irregular in size and not very closely set. The Palp arises laterally at the side of the proboscis (fig. 2a), and comprises the normal five joints, all of which, except the first, are very long and slender, the pro- portions being 10:10:9:11. Setse are non-existent on the first two joints ; on the third scanty, most numerous on the terminal joint, but not very thickly distributed there ; they are small, rather delicate, and occur mainly on the outer side of the limb. The Oviger has the normal ten joints, and arises on a small ventro-lateral body- process just in front of the first pair of lateral processes (fig. 2b). The first three joints are small, but progressively lengthen, the third having the usual oblique termination. The fourth joint is long, the fifth longer, and the sixth still long, though the shortest of these three, the proportions being about 7:8:5. The sixth joint is rather thinly covered with small setae on its outer side, and has a well-developed distal fringe. The preceding joints have so few minute setse between them that they are scarcely noticeable. Of the four terminal joints, the first is about twice the length of the next ; the other three differ very little in size, but the middle one is the smallest. All are provided with a few small setae and distal fringes. The terminal claw bears a dozen slender teeth rather closely set. The denticulate spines form a single row (plate X., fig. 9). They consist of a stout shaft, which begins to taper at about a quarter of its length, where the denticulations begin. Of these there are from five to seven ; the first is small, the next three large, and the remainder more or less vestigial. Of these spines there are 10:5:4:5 respectively on the various joints. The Legs are long and slender, attaining a length of nearly 45mm. The three coxae are long, the second being longer than the other two together ; these joints are rather scantily clothed with setae of no great length. The proportions of the following- joints are 8'5 : 9'5 : 12 : 4 : 3. The terminal claw is very long and slender, more than half the length of the propodus, and there are no auxiliaries. The limb is clothed with setse, not very closely set, in a linear manner. On the femur and tibia they are very long and slender, becoming reduced in size on the tarsus, while on the propodus they are very small. Two examples of this species were taken off the Barrier in 300fm., bottom mud, 27th January, 1902. NYMPHON ADAREANDM. (Plate III., fig. 3.) Specific characters : - Body smooth and slender, with lateral processes widely separated. Ocular tubercle short, rounded. Palps five-jointed, proportions of last three 2'5 : T25 : 1'75. Oviger ten-jointed, without denticulate spines, but with very few simple curved spines. Legs of moderate length, with rather long setse, terminal claw with two well-developed auxiliaries. VOL. III. P 24 T. V. HODGSON. This small species has a fairly well-built body, with the lateral processes rather widely separated, and as long as the diameter of the trunk. The trunk articulations are very distinct, and immediately behind the lateral processes. No setse of any kind are to be seen on the body. The Cephalon is stout but not widely expanded, showing two distinct lobes for the reception of the chelifori ; it is not quite as long as the second and third trunk segments together. The Ocular tubercle is very stout, of small elevation, rounded at the summit, and carries four well-developed eyes. It lies just in front of the first pair of lateral processes and behind the neck. The Abdomen is of moderate dimensions, curved upwards, and not separated by an articulation from the trunk. The length of the body is 275mm., and its extreme width l'5mm. ' The Proboscis arises on the ventral side of the trunk, and measured vent-rally it is nearly one-third the length of the entire body. It is stout, gently tapering to a rounded extremity, quite smooth. The Chelifori are well developed ; the scape is single-jointed, extending beyond the proboscis ; provided laterally with comparatively long setse. The chela is not very long, the palm and fingers occupying approximately equal halves ; the former is covered with setse, and the fingers, rather curved, are supplied with a very moderate number of slender teeth rather widely separated. The Palp is five-jointed, and rises underneath the chelifori (fig. 3 a) ; as usual, the first joint is very small and the second long. Owing to distortion in mounting this appendage, the comparative length of the second and third joints cannot be very accurately stated, but the second appears to be twice the length of the third ; the fourth is half the length of the third, and the fifth is longer than the preceding, the proportions being 5 : 2'5 : T25 : 175. The terminal joint is ovoid, and fairly well supplied with comparatively long setae ; the three preceding joints have well-developed distal fringes and a small number of setse scattered along the shaft ; these are most numerous on the third joint. The Oviger is ten-jointed, and rises from a small process of the trunk, visible dorsally, just in front of the first pair of lateral processes (fig. 3 b). The first three joints are very small ; the second and third are subequal in length, the latter much the more slender ; the fourth is longer than the three preceding ones together ; the fifth is twice as long, much curved, and bears a few setae on its outer margin ; the sixth is half as long as the fourth. The four terminal joints are very small, the first being the largest, and all bear two or three long setse distally. The terminal claw is long and slender, with five slender teeth set at irregular intervals. Of denticulate spines, such as characterise the genus Nymplion, there are none, but of special spines there are 2:2:2:1 on the four joints ; these are curved blades without any other distinguishing feature. PYCNOGONIDA. 25 The Legs are not very long, extending to nearly llmm. from the trunk. Of the three coxa?, the second is as long as the other two together, the first being by a little the smallest ; the proportions of the remaining joints being 4 : 5 : G : 075 : 2. The terminal claw is large and stout, with two well-developed auxiliaries. The lateral line is distinct throughout. The seta; have a rather indistinct linear arrangement, those on the sides of the coxa; are prominent, especially on the second ; on the third they are more confined to the ventral surface, and the distal fringe is fairly well developed. On the femur the seta; are long and straggling, chiefly lateral, and ventrally there is a row of small tubercles. On the two tibia;, but more especially the second, the seta; are most abundant, largest on the first. Ventrally they are much smaller, the distal fringe of the second tibia becoming spinous. The tarsus is a very short joint with long seta; dorsally, smaller and more numerous ones ventrally, which become delicate spines distally. The propodus is covered with seta; dorsally, and ventrally there is a row of rather strong spines, and of these the middle ones are strongest. The single specimen is a male, carrying young, apparently just hatched. The Genital apertures are to be found on the second coxa} of the two posterior pairs of legs. From the root of a Lamiuarian taken iu 17 fm., Cape Adarc, 24th February, 1904. NYMPHON FRIGIDUM. (Plate III., fig. 4 ; Plate X., fig. 10.) Specific characters : — Body very slender, with lateral processes long arid very widely separated. Ocular tubercle very short, stout. Palps five-jointed, proportions of last three 3 : 1'5 : 3. Oviger ten-joiuted, denticulate spines not very numerous, with five to seven lateral teeth. Legs long and slender, propodus with ventral row of spines, a large terminal claw and two auxiliaries. Body well built, perfectly smooth, with the lateral processes widely separated and rather long, much more slender than the trunk. The Cephalon is rather long, with a distinct neck and expanded anteriorly into the two normal lobes. The Abdomen is short, directed obliquely upwards, and not projecting beyond the posterior pair of lateral processes. The Ocular tubercle is stout, very short, and bears four well-developed eyes. The length of the body is 2mm., and its extreme width is 1 '2mm. The Proboscis is cylindrical, directed downwards. The Chelifori comprise a single-jointed scape, slender, and covered with a small number of fine seta;. The chela; are well developed, the palms being about half their length, and setose ; the fingers are not much curved, provided with a number of teeth, not very closely set, and of uniform size. The Palp is five-jointed and rises underneath the chelifori (fig. 4a). The first 26 T. V. HODGSON. joint is small, and the proportions of the remainder are 4:3: 1'5 : 3. The terminal joint is well supplied with setae on the outer side, and the preceding one is similarly, but less well, provided. Elsewhere they are scanty, a few on the third, and only an occasional one on the second. The Oviger is ten-jointed, and rises from a small process immediately in front of the first pair of lateral processes (fig. 4b.) The first joint is very small, the two following are longer and subequal, the third having as usual a very oblique termination. The fourth and fifth joints are subequal, and each much longer than the first three together ; the sixth is half as long as the preceding. Of the four terminal joints the first is the longest, the rest differ but little, but the last is longer than the others, and bears a terminal claw with some half-dozen teeth. A limited number of setae occur on all the joints from the end of the fourth. The denticulate spines are not very numerous, 8:5:4:5, and consist of a slender tapering shaft with from five to seven lateral teeth ; the second from the base is strongly developed, the rest graduated to nothing (plate X., fig. 10). The Legs are long and very slender ; they are about 9mm. long. Of the three coxae the second is longer than the other two together, the proportions of the remaining joints being 4 : 4'5 : 7 : 1 : 1'5. The terminal claw is more than half as long as the propodus, and is accompanied by two slender auxiliaries. The entire limb is rather thinly clad with setae, which, as usual, are most abundant on the second tibia. The propodus bears ventrally a row of comparatively strong spines, not very regular, the middle ones being generally best developed. This is not a mature form, and the sexual apertures cannot be distinguished. I am unable to identify it with Nymphon hiemale, though it occurs in the same locality, and feel compelled to regard it as an independent species. CH^TONYMPHON VILLOSTTM. (Plate IV., fig. 1 ; Plate X., fig. 11.) Specific characters : — Body robust and with the appendages covered with long and fine seta; ; lateral processes close together. Ocular tubercle rather tall, with four eyes at summit. Palp five-jointed, proportion of last three 6:2:3. Oviger ten-jointed, denticulate spines not numerous, having five to seven lateral teeth on each side. Legs short, with a strong terminal claw and two well-developed auxiliaries. Body very robust and, with the appendages, covered with long and fine setse. The lateral processes are close together, and these, being stout, give the body a compact ovoid form. The Cephalon is short, much expanded, and the neck, which thereby becomes distinct, is scarcely a real constriction, the expanded portion being divided into two distinct lobes, bearing a few long, setae distally. Similar setae occur dorsally on PYCNOGONIDA. 27 each segment of the trimk and on the lateral processes, in addition to the distal fringe. There are none veiitrullv. The Ocular tubercle rises from the neck immediately in front of the first pair of lateral processes ; it is moderately tall, cylindrical, and bears at its rounded summit four well -developed eyes. The Abdomen is long and slightly ovate ; it projects beyond the first coxae of the posterior pair of legs in their normal position, and bears a few small setae. The length of the body is G'5mm. and its width is scarcely 4mm. The Proboscis is stout, cylindrical, and inclined downwards ; it is quite devoid of setae of any kind, and 2'5mm. long, measured dorsally. The Chelifori are strongly developed ; the scape is stout and single-jointed ; it bears on its inner margin a band of long setse and a distal fringe of similar setae, but these are much reduced in size on the outer side. The chela is strong, the palm is setose all over and well on to the base of the immovable finger. These setae are of normal size. The fingers are inclined at a considerable angle with the palm, and are curved at the tips, especially the immovable one. Both are provided with numerous slender teeth, not very closely set, and variable in size ; these teeth may be said to be large and small, but they are not disposed with any regularity. The Palp has the normal five joints and arises at the side of the proboscis (fig. la)- The first joint is very short and stout; the second is the longest; this is stout, dilated, curved at its distal extremity, sparsely covered with long setae and much more abundantly with fine ones. The third joint is nearly as long, as 8 to 10, and more abundantly supplied with both kinds of setae, which occur throughout the appendage. The fourth joint is short and richly setose ; the fifth is about half as long again as the fourth, and also richly setose. The Ovigers arise ventro-laterally, immediately in front of the first pair of lateral processes (fig. Ib). Of the orthodox ten joints the first three are quite small, the last being slightly curved, longer than either of the other two, and with an oblique termination. The fourth joint is long, the fifth is longer still, the sixth about half the length of the preceding. All these joints are covered with very fine setae ; on the first four there is an occasional longer and coarser seta, and on the fifth joint these are more conspicuous on the outer margin and distal extremity ; on the sixth joint they cover it on the outer side and form a well-developed distal fringe. Of the four terminal joints the first three progressively shorten without any conspicuous difference in size ; the terminal one is a little longer than the preceding, and bears a slender curved and dentate claw half as long again ; there are eleven slender teeth on the claw. The denticulate spines are not numerous on these joints, 5:4:3:4, and are of the normal type, the shaft bearing five to seven lateral teeth. The spines on the proximal joint an- the largest. (Plate X., fig. 11.) The Legs are short and robust, only attaining a length of 17mm. Of the three <'nxse the second is a little the largest ; they all bear a few long setae dorso-laterally, the T. V. HODGSON. third coxa being the most deficient in this respect. The distal fringe is well developed ventrally on the second coxa, but more so on the third, and the ventral surface of this joint is covered with small setse. The femur is short and stout, approximately equal in size to the second tibia, the first being a little longer. The setse on these three joints are arranged in a thoroughly characteristic manner. There are two dorso-lateral rows and a lateral row, all of long, slender setse. There is also a ventral row of com- paratively short setse, five rows in all. The setse are much better developed on the second tibia than elsewhere. The distal fringes on these joints are normally developed ; on the tibise they are ventral and spinous, more especially on the second tibia. The tarsus and propodus are short and much more slender than the rest of the limb. The two joints differ but little in size, the propodus being a little the longer. This bears a stout terminal claw and two well-developed auxiliaries. The setse of these two joints are small, but have the same arrangement as on the other joints. The ventral row is, however, distinctly spinous, and a very prominent spine exists at the ventral end of the tarsus. Only one individual of this species was taken, and its sex has not been determined. Coulman Island, 13 January, 1902 ; 100 fathoms, stony bottom. CELETONYMPHON BIARTICULATUM. (Plate IV., fig. 2 ; Plate X., fig. 12.) Specific characters :— Body stout, tapering posteriorly, articulation deficient, lateral processes separated by variable intervals. Ocular tubercle long and slender. Palps five-jointed, proportions of last three as 3 : 1 : 1. Oviger ten-jointed, denticulate spines not numerous, and with not more than five small teeth on each side. Legs of moderate length, covered with rather fine seta?, terminal claw with small auxiliaries. Body is stout and tapering posteriorly, with the lateral processes separated by a moderate interval, except the last two pairs, which are quite close together, the articu- lation between them being deficient. The distal extremities of the lateral processes are provided with slender spines, but these have enlarged bases and thereby become more prominent. The Cephalon is short and stout, a very distinctly constricted neck separating the expanded portion, which forms two diverging lobes. The Ocular tubercle lies immediately behind the neck and in front of the first pair of lateral processes. It is tall, slender, cylindrical, and bears four well-developed eyes at the extremity ; there is no pigment. The Abdomen is rather long, narrow, tapering to a blunt point, and not separated from the trunk by an articulation. The entire body is covered with very fine setse, not easy to distinguish, and in addition there are two long setse dorsally near the posterior border of each segment, PYCNOGONIDA. 29 two on each of the cephalic lobes, and one in the middle of each lateral process ; these also possess dorsally a distal fringe of stout sette with enlarged bases. The ventral surface appears to be quite devoid of setae. The length of the body is 9mm. and its width scarcely 5mm. The length of the trunk only (to base of abdomen) is 6mm. The Proboscis is stout, cylindrical, and has a length, measured dorsally, of 3mm. It is covered with very fine but comparatively long setae. The Chelifori are well developed. The scape is single-jointed, reaching beyond the proboscis ; it is stout and provided with rows of setae having very stout bases and a few others as if misplaced. The distal fringe is very prominent, especially on the inner side. The chela approximately divides its length between the palm and the fingers ; the former is covered with short and comparatively fine setae, and these are continued well on to the base of the immovable finger. The fingers are inclined inwards, slender, much incurved at the tips, and furnished with a number of slender, closely-set teeth of fairly regular size. The Palp arises laterally immediately below the chelifori (fig. 2a). The first joint is small and stout, the second is long, and extends nearly to the end of the proboscis ; the third is shorter ; the two terminal ones subequal and together shorter than the third, the proportions of the four joints being 5:3:1:1. The second joint is uniformly covered with fine setae, as are the others. The setae become more numerous and both longer and stiffer towards the extremity of the appendage. The Oviger rises ventro-laterally immediately in front of the first lateral process ; it consists of the normal ten joints, and is covered throughout with very fine delicate setae (fig. 2b). Other and stiffer setae occur sparingly on the fifth joint, more numerously on the sixtli and the distal fringes of most of the joints, particularly the terminal ones. The first three joints are small, but progressively lengthen, the third having a very oblique termination. The fourth is a trifle longer than the first three together, the fifth is longer still, and the sixth is half the length of the fifth. The four terminal joints progressively shorten, the third being practically half the length of the first ; the terminal one bears a slender curved claw, as long as itself, with nine slender teeth. The denticulate spines are not numerous, 7:5:4:4 (Plate X., fig. 12). They consist of a flattened tapering shaft with not more than five lateral teeth on each side, none of them large, and occurring nearer the base than usual, leaving the terminal portion of the shaft free. They do not appear to be much worn. The Legs are not very long, extending to about 25mm. Most of the joints aiv very stout, but the tarsus and propodus are considerably reduced in diameter. Of the three coxse the second is the largest, but not so long as the other two together ; the proportions of the remaining joints are 5'5 : G : 5'5 : 3 : 2. The entire limb is clothed with fine setae, but in addition to these are conspicuous rows of spiuous setae arising from enlarged bases. Two dorso-lateral rows occur on the first two 00x33, two rows occur dorsally on the femur, but here the spines are small ; the two lateral rows are 30 T. V. HODGSON. much larger ; but ventrally, this joint and the coxae also are covered with normal setae. These spines are best developed on the first tibia, two dorsal and two lateral rows being conspicuous, a ventral row of much finer spines occurs. On the second tibia all these five rows occur, but the spines are rather finer. The setae of the two terminal joints are small without the enlarged bases, but arranged in the same manner. The terminal claw is long and slender, and is accompanied by two quite small auxiliaries. The distal fringes of the various joints do not present any unusual features. The single specimen is a female, the Genital apertures are conspicuous on the second coxae of all the legs. Off the Barrier. January 27, 1902. 300 fms. Mud. Lat. 78° 25' 40" S., long. 185° 39' 6" E. CH^ETONYMPHON MENDOSUM. (Plate IV., fig. 3 ; Plate X., fig. 13.) Specific characters : — Body robust and tapering, articulation imperfect, lateral processes not widely separated, and with stout spines distally and dorsally ; no fine setiB whatever. Ocular tubercle short and stout. Palp five-jointed, proportions of last three 5'5 : I'o : 1'6. Oviger ten-jointed, denticulate spines few, with four teeth on each side, two of them prominent. Legs with five rows of spinous setae, without enlarged bases ; terminal claw with two small auxiliaries. This species is very closely allied to the last, but is much smaller, and presents other differences which are usually regarded as of specific rank. The Body is robust and slightly tapering, with stoutly developed lateral processes, the intervals between which are variable, widest but not very wide between the first and second pairs ; the third and fourth being quite close together, the articulation between the two posterior pairs is not present. The Cephalon is short, anteriorly expanded into two diverging lobes ; the neck is distinct, but very little constricted. The Ocular tubercle lies behind the neck, but not clear of the first pair of lateral processes. The Abdomen is horizontal, long, extending considerably beyond the first coxa, ovoid, tapering to a blunt point ; it completely fills the space between the two posterior lateral processes. All this is in close agreement with the preceding species. The differences are : — The complete absence of fine setae from the entire body ; the ocular tubercle is rather short, stout, and slightly inclined forwards, carrying four well- developed eyes with pigment on its rounded summit ; the lateral processes all provided with two or three stout spines dorsally and distally ; the spinous setae of the legs, while having the same 'arrangement as in the preceding species, are, on the whole, stronger in themselves, but without the enlarged bases. The length of the body is G'Smm'., and its width just exceeds 3mm. PYCNOGONIDA. 31 The Proboscis is of moderate length, 2mm., measured dorsally, cylindrical Imt slightly swollen in the middle ; it is directed downwards, and not setose at all. The Chelifori are well developed ; the scape is single-jointed, stout, and scarcely as long as the proboscis. A row of stout spines runs along its inner border, and a few spinous setae constitute a distal fringe, and there are two or three scattered on the shaft. The chela is strong, the palm taking up half its length, and the fingers are set at a considerable angle. The palm is covered, but not thickly, with setae. The fingers are slender, curved towards the tip, and provided with slender teeth of fairly uniform length, but not very closely set. The Palp rises laterally, quite close to the proboscis, and consists of the normal five joints (fig. 3a). The first is short and stout, the second is the longest of the appendage and provided with a few long setae ; its proportion to the remainder is 9 : 5'5 : 1'5 : 1'6 ; the third is scantily supplied with setae, the two terminal joints are rather more abundantly supplied ; the last joint is ovoid instead of cylindrical. The Ovigers arise ventro-laterally immediately in front of the first pair of lateral processes. They comprise ten joints of normal character (fig. 3b). The first three joints are quite short, stout, and progressively lengthening ; the proportions of the three following are 7:9:5. Setae become prominent, but not numerous, on the fifth and sixth joints ; on the preceding joints they are almost non-existent. The four terminal joints are small, the proportions being about 4'5 : 3 : 2'5 : 2'75, the last one possessing a curved terminal claw, quite as long as the joint, with half-a-dozen rather widely separated teeth. All the terminal joints carry a few setae distally and dorsally. The denticulate spines are not numerous, 5:4:3:4 respectively ; they consist of the normal flattened blade with two prominent teeth on each side, and two others of which traces remain. They are rather worn. (Plate X., fig 13.) The Legs are rather short, about IGrnm., very stout, but the tarsus and propodus are very much reduced in diameter. Of the three coxae the second is much the longest, but not so long as the other two together. The first is provided dorso-laterally with two stout spines, and there is another rather smaller one laterally, on the posterior side. A row of spiuous setae occur laterally on the other two coxae. The distal fringes of these two joints are ventral and inconspicuous ; that of the third coxa is the best developed, and on this joint there are several small. setae ventrally in addition. The three following joints are subequal in size, the tarsus and propodus together are three-quarters the length of the preceding joint, and are themselves sub- equal. In these particulars this species is not in agreement with the preceding. On the two tibiae there are two dorsal rows of stout spiuous setae, a lateral row on either side, and a strongly developed ventral row. On the second tibia the distal fringe is strongly developed ventrally, and spinous. The setae on the femur are smaller, and only the two dorsal rows arc distinct ; the other three rows are present, but very feebly developed ; there is a prominent distal fringe dorsally. The tarsus and propodus are similarly provided, but the setae are much smaller. The terminal claw VOL. III. Q 32 T. V. HODGSON. is stout, iiot half the length of the joint that bears it, and provided with two small auxiliaries. The specimen described above is an adult female with Genital apertures on the second coxae of all the legs. Nearly mature ova can be seen in the femora. It was taken in Winter Quarters, in 125fni., 24 April, 1903. Bottom : small stones, organic debris, polyzoa, shells, etc. Other specimens, generally smaller, were taken at the same place on various dates, and also at other points three and nine miles away, and at the same or greater depths, 180 fm. They all appear to be sexually mature, and differ in a varying degree from the type in their spinose character. In all cases this is more conspicuous in the males. The Genital apertures of the male are on the two posterior pairs of legs only. The numerous minor features which separate this species from the preceding cannot, in my opinion, be ascribed to age. The form of the ocular tubercle readily separates the two. A specimen was taken in 125 fm. on 3 May, 1903, and is, I think, a young form of this species. The differences between this specimen and the adult individuals are : — The posterior articulation of the trunk is present, but very much less distinct than the others. Palps : the second joint is as long as the three following together. The third joint is as long as the two terminals together, and of these the last is a little the longer. Ovigers : these are quite rudimentary, small, and hook-like ; no joints are differentiated, though two are indicated. Legs : the proportions of the joints differ somewhat and are, beginning with the femur, 6:7:7: 2'25 : 3'5. The limb is clothed with comparatively strong spiuous setse of some length, not very numerous, arranged in lines. CH^TONYMPHON AUSTRALE. (Plate X., fig. 14.) Nymphon austrrth, Hodgson (10), p. 257. Chcrtonymphon ciUiomlatum, Mobius (23), p. 181. Specific characters : — Body robust, with lateral processes not widely separated but divergent ; entire animal rather coarsely setose. Ocular tubercle long and slender. Palps five-jointed, proportions of last three as 7 : 4'25 : 4. Oviger ten-jointed, denticulate spines fairly numerous, with four distinct lateral teeth on each side. Legs short, tarsus a little longer than the propodus, the terminal claw with very miiiute auxiliaries. Body robust, with stoutly developed lateral processes, which are distinctly though not widely separated, the interval increasing with age ; the body, exclusive of the anterior part of the cephalon, forming an oval of graceful proportions. The Cephalon is expanded, and the space between the chelifori is marked by a deep groove, wide anteriorly. The neck is well defined, and behind this is the Ocular PYCNOGONIDA. tubercle, a structure which varies considerably in shape and size. As a rule it is rather stout, and bears four well-developed eyes, with a variable amount of pigment. It is slightly flattened antero-posteriorly, and more or less rounded at the extremity. The cephalon and the lateral processes are provided with several long setae, the latter also having a distal fringe. The Abdomen is of moderate dimensions, pyriform, and rather thickly setose, not separable from the trunk by an articulation. The Proboscis is cylindrical, slightly enlarged about its middle. It is directed downwards, and movably articulated to the trunk. No setge are apparent on its surface. The length of the entire body is 8mm. ; of the body only, Grnm. ; of the trunk, to the insertion of the abdomen, 4 • 5mrn. Its width is 3mm. The Chelifori are well developed ; the scape is a single joint longer than the proboscis, liberally provided with long setae of irregular size, and also having a well- marked distal fringe. The chelae are slender, about as long as the scape. The palm occupies half the length of the entire chela, and is covered with comparatively long setae, which are continued far on to the immovable finger. The fingers are slender and much incurved at the tips ; they are provided with a large number of closely set teeth of irregular length. The Palps are slender and five-jointed. The first joint is quite small, the second is the largest of all, and rather sparingly provided with setae, which are longest on its outer side ; the third joint is a little shorter, slightly enlarged distally, the setae being more numerous and more uniform than on the preceding joint. Of the two terminal joints the distal one is a little the shorter, but together they exceed the length of the second by a trifle. These two joints are richly setose, particularly on one side. The Oviger is ten-jointed ; in the female the first three joints are very small, but progressively increase in length. The fourth and fifth are subequal and much the longer of the whole series, and slightly curved in opposite directions. The sixth joint is about three-quarters the length of the fifth. Of the four terminal joints the first three progressively shorten, the terminal one being a trifle longer than the preceding, and it bears a long slender pectinate claw with eight teeth. The first four joints bear scarcely any setae, except an inconspicuous distal fringe ; on the fifth the setae are noticeable on its outer border, and those of the distal fringe are rather long and slender. In this particular the sixth joint is similar. The four terminal joints are all provided with a distal fringe and a number of long setae. The denticulate spines are arranged as usual in a single row, and, counting the joints from the base of the appendage, they bear respectively 9 : 7 : 5 : 7 of these spines (Plate X, fig. 15). These numbers are not, however, rigidly adhered to. The spines consist of flattened shafts of a slightly sinuous form, bearing four well-developed teeth on each side, with traces of a fifth in large and uninjured specimens. The third tooth from the base is usually the Q 2 34 T. V. HODGSON. largest. In the fully developed male the fifth and sixth joints are remarkably swollen. The enlargement of the fifth joint affects the distal half. The eggs are large, and the spherical masses may be two in number on each limb ; they are carried round the fourth joint. The Leg extends to a length of 21mm. These appendages do not differ appreciably in size. Of the three coxae the second is much the longest, but not so long as the other two together. The proportions of the three following joints are as 4:5: 4'5. The tarsus and propodus together are as long as the femur, the former joint being the longer of the two. The terminal claw is well developed, and is accompanied by two very minute auxiliaries, not one, as stated in the ' Southern Cross ' Collection, Crustacea, p. 258. The entire limb is setose throughout, the setse abundant, and variable in size, some of them distinctly spinous. For the most part their arrangement is irregular, but on the second tibia a linear arrangement begins to be perceptible, and this is clear on the tarsus and propodus, where the setse are much finer. The distal fringe of the first coxa is dorsal, and not so strongly developed as on the two following joints, more especially the third, where it is ventral. On the femur it is chiefly dorsal, and the setae composing it are long and stout. On the first tibia it is complete and rather spinous ventrally ; this is more strongly developed on the second tibia, where there is at least one powerful spine ventrally, and generally two on each side. The male differs from the female in being more setose, the setse being longer, more irregular, but scarcely, if any, stronger. The distal fringe of the third coxa is particularly noticeable for the great length of the setse composing it. The Genital apertures of the female are conspicuous on the second coxa of all the legs ; those of the male are much smaller, and can only be detected on the two posterior legs. This species was taken in considerable numbers off Cape Adare, but inside Robertson Bay, in 20-26 fm. None were taken by the ' Discovery.' I have re- described it here to remove certain defects of the original description, and on account of the capture of a form which, after considerable hesitation, I feel compelled to regard as only a variety. This species is closely allied to N. brevicaudatum Miers, with which N. korridum Bohm has been identified by subsequent investigators. N, brevicaudatum Miers, can be readily distinguished from N. australe by the following characters :— The trunk is more setose. The tarsus is shorter than the propodus. The terminal claw has two distinct, if small, auxiliaries. The oviger bears a very much smaller series of denticulate spines, but their lateral teeth are more numerous. I am unable to regard the C/isetonymphon altioculatum of Mobius as a distinct species, several examples of which were taken in the vicinity of Bouvet Island during the ' Valdivia ' expedition. PYCNOGONIDA. 35 CH.ETONYMPHON AUSTRALE, var. AUSTRINORUM. (Plate IV., fig. 4 ; Plate X., fig. 15.) Although no specimens of ChsetonympJion australe were taken by the ' Discovery,' yet a large number of individuals of a closely allied species were taken in Winter Quarters, chiefly at the beginning of our stay there, before the ship was frozen in, and while dredging was still possible within the 20-fathom line. At first sight these specimens seem to be a distinct species ; they are half as large again or more, and their setose covering is finer. The intervals between the lateral processes are much greater, and this is the only character of importance that separates them. Another feature of doubtful value lies in the fact that the tarsus and propodus together are distinctly shorter than the femur. In C. australe these two joints are as long as the femur, or very little shorter, but the slight variation that occurs prevents the acceptance of this fact as a reliable specific character. The setose covering has already been alluded to as finer ; it is so, but subject to considerable variation both as to quality and quantity. In average specimens there are large spinous setae on the tibiae, especially on the second. These are, for the most part, arranged in a line but not very distinctly. Two dorsal rows, and a lateral row each side can be distinguished, these are most prominent on the second tibia. There may also be a mid-ventral row of very small spinous setae, rather closely set. Both in C. australe and the specimens from Winter Quarters the ventral setae of the femora and the two tibiae are much less conspicuous than elsewhere. In many indi- viduals there is a conspicuous mid- ventral row of setse on the tarsus ; these are closely set and about as long as the diameter of the joint. Two specimens were taken in lOOfin. off Coulman Island ; of these one is com- paratively small. The Ocular tubercle is rather more conspicuously flattened and very slio-htly constricted below the eyes. The setae are as in the Winter Quarters specimens, but without the spinous rows which, as before noted, are not always obvious. Two other specimens were taken off the Barrier in 300fm. Lat. 78° 25' 40" S., long. 185° 39' G" E. These are both males, one with young. In these the Ocular tubercle is flattened, as in the Coulman Island specimens, and the terminal claw of tin- leg is rather longer and more slender. The setose covering of the legs is very much finer, but its arrangement is exactly the same. It is quite impossible to find a distinct character by which these specimens can be separated from C. austral', therefore I feel compelled to regard them as a variety only, and a more southern form of that species Some comparative measurements are given below. C. australe. C. austrak, var. austiinornm. W. Q. Coulman. Barrier. Length of entire body . . . . 8111111. 11 7 12 \-> Length of body 6mm. 8 5'5 'J'5 9'5 Length of trunk, to insertion of abdomen 4'5mm. 047 7 36 T. V. HODGSON. C. australe. C. australe, var. austrinorum. W. Q. Coulman. Barrier. Length of abdomen . . l'5mna. 2 T5 2'5 2'5 Width of trunk . . . 3mm. 4 3 scarcely 5 scarcely 5 Length of third leg . . . . 21mm. 31 18 32 37 Proportions of femur and two tibia? . 4 5 4'5 6 7'75 7 6 9 8 7 9 8'5 3-5. 4-5 4 Tarsus and propodus together . As long as femur, Shorter than femur or very nearly. In all cases the tarsus is longer than the propodus. The Palps are alike in all cases, but these have not been accurately measured, as this cannot be done without removal. Fig. 4a is that of a Winter Quarters specimen. The Ovigers are essentially alike, the differences between one or two of the joints beino- very trivial (fig. 4b). The number of denticulate spines is too irregular to be of any value. 99:7:5:7. 9 11 : 7 : 5 : 8. $ 11 : 9 : 7 : 9. The character of these spines is shown in Plate X., fig. 15. The sexual difference in these organs is the same in all, and the ova, which are known in all but the Barrier specimens, are large and attached to the oviger in precisely the same way. PENTANYMPHON. Body smooth, very slender, with lateral processes widely separated. Five pairs of legs. Chelifori well developed, chelate ; scape a single joint. Palps five-jointed. Ovigers ten-jointed, terminating in a pectinate claw, the last four joints with a single row of denticulate spines. But for the additional pair of legs it would be quite impossible to separate this genus from Nymphon. Only a single species is for the present recognised, and this appears to have a circumpolar distribution. It has been taken by the Scotch, German, and French Expeditions. PENTANYMPHON ANTARCTICTJM. (Plate V.) Pentanymphon antarcticum, Hodgson (11), p. 458 ; Cole (7), p. 405 ; Bouvier (3), p. 294. Specific characters : — Body very slender, lateral processes long and widely separated, neck very long. Chelifori : chela: long and slender, shorter than scape, with short, stout, uniform, close-set teeth. Palps : terminal joint longer than preceding, which is in turn half the length of the third. Ovigers : terminal claw pectinate, denticulate spines, with seven pairs of lateral teeth, the first being very small. Legs rather long and slender, with a well-developed terminal claw and two auxiliaries ; settc arranged in four rows on the last three joints. PYCNOGONIDA. 37 The body is very slender, quite smooth, with very widely separated long lateral processes. Anteriorly it is slightly curved downwards. The Cephalon is long and slender, longer than the second and third segments, and expanded di.stally into two dorsal lobes for the articulation of the chelifori. The Ocular tubercle lies immediately in front of the first pair of lateral processes. It is short, merely a low rounded hump, in fact, bearing four well-developed eyes. The Abdomen is very small, directed upwards, and not separated from the trunk by an articulation. It is rather conical and extends but little beyond the trunk, not nearly so far as the posterior lateral processes. The segmentation of the trunk is distinct, the joints occurring immediately behind the lateral processes. The Proboscis is directed downwards, cylindrical, with a slight swelling about the middle of its length ; it is as long as the cephalon, and its extremity is rounded. The Chelifori arise above the proboscis, each on a lobe of the cephalon, which is here rather more than twice its diameter posteriorly. The scape is single-jointed, longer than either the proboscis or the chela. A few delicate setae are scattered along its length, and there is an inconspicuous distal fringe. The chela is a little shorter, the palm and dactyli occupying equal halves ; the former is covered with fine setae which also form a fringe round the base of the movable finger. The fingers are slender and much curved near the tips. Both are provided with a row of fairly stout teeth of nearly uniform size, rather closely set. The Palps arise below the chelifori and at the sides of the proboscis ; they are built on exactly the same plan as in the genus Nymphon (fig. la). The first joint is small and stout, the proportions of the remainder being 8:5:3:4. The second joint is sparingly setose except for a distal fringe ; the other joints become more and more setose to the last, which is richly supplied. On the outer side they are more abundant than elsewhere. The Ovigers are ten-jointed and present in both sexes. (Fig. 1 b. ) They arise from very short but conspicuous processes on the lower side of the cephalou, immediately in front of the first pair- of lateral processes. The details of this appendage are as in Nymphon. The first joint is very small, the second is twice the size, and the third, which has a very oblique termination, is a little longer still ; none of these bear setae. The fourth joint is very long, slender, and slightly curved ; it carries a glandular aperture on its outer side about a quarter of its length ; all the setae are small ; very few occur except as a distal fringe. The fifth joint is longer still, the longest of the appendage, and its distal half is enlarged in diameter ; it is covered throughout with fine setse. The sixth joint is rfither more than half the length of the fifth, slightly curved, and on the outer side of the curve plentifully supplied with fine sette. Of the four terminal joints the first is little more than half the length of the preceding, the other three are shorter and sub-equal ; very few setae occur, except distally. They carry a single row of denticulate spines (fig. !(•). These T. V. HODGSON. spines consist of a slender shaft with a swollen base ; near the base is a pair of small teeth followed by two pairs of comparatively long slender ones ; the remaining four pairs are more slender and blade-like, graduating to a mere trace. The terminal daw is furnished with about nine slender teeth. Both denticulate spines and terminal claw are frequently very much worn. With regard to the Legs, all five are practically of the same size and proportions, and though there is a considerable amount of variation in this respect it is confined to narrow limits. They may attain a length of as much as 36mm. Of the three coxse, the first and third are sub-equal and together about as long as the second ; all, especially the third, bear a few minute setse, chiefly ventral. The proportions of the three following joints are approximately as 6 '5 : 7 and 10 ; the tarsus and propodus are long and slender, the former being the longer. The limb is more or less covered with fine setse. On the femur they are scanty and for the most part small ; a few longer ones are to be found along the shaft and distally. On the first tibia they are comparatively long and arranged in four indistinct rows, of which the lateral ones are not easy to observe. On the second tibia they become smaller and much more numerous, especially distally, and the distal fringe is strongly developed ventrally. The same arrangement holds good for the two remaining joints, but the ventral row is very strongly developed, the setse becoming almost spinous and closely set. The terminal claw is a powerful one, and is accompanied by two slender auxiliaries of about quarter its size. The Genital apertures of the female are found on the second coxse of all the legs and in the adult they are distinct enough. The apertures of the male are at all time? difficult to observe, and I have only been able to distinguish them on the three posterior pairs of legs. Nearly thirty specimens of this species were taken in Winter Quarters, at all times of the year, and in depths ranging from 12 to 125 fathoms. They vary considerably in size, a variation obviously due to age, but in essential details they are in agreement except in one particular, and that is the articulation of the abdomen to the trunk ; in certain cases among the more robust forms it is distinctly articulated. The trunk in all cases is seen to be very minutely scabrous when removed from spirit. The females are more robust than the males when the sexes can be separated, a feature which is most noticeable in the femora, but extends to the first tibise. The males, as a rule, are rather more setose than the females. A few of the eggs borne by one of the males are hatched. On emerging from the egg the body is ovoid, and possesses three pairs of appendages. The cheliforus comprises a stout scape with one very long seta, and a small but well-developed chela, without teeth on the dactyli ; a small proboscis lies below these. Details of the other two pairs of appendages cannot be seen without special preparation, which has not as yet been undertaken. Other specimens crawling about the egg-masses show the proboscis, chelifori, the palps not clearly jointed, and four pairs of appendages, having PYCNOGONIDA. 39 three stout sub-equal joints, followed by a fourth nearly as long as the three together, only a great deal more slender, and terminating in a very minute claw ; a conical abdomen lies at the extremity of the trunk, the posterior part of which is provided with a small number of very long setae. LEIONYMPHON. Prof. Mobius (23) has described this genus as follows :— " Korper kurzhaarig. Rumpf breit. Beintriiger am Grundc zusammcnstosscnd. Hals kurz and breit. Augenhiigel konisch mit 4 Augen. Riissel walzenformig. Finger oliuc Zahne. Pal pen neungliedrig. Brutbeine zehngliedrig, 7. Glied beim Miinncheu kurz und dick ; allc Gliedcr nur kurz bekaart." LEIONYMPHON, n.g* Rumpf cbenso breit wie lang. Die beintragenden Seitenforsatze der Rumpfglieder stossen zusammen. Kopf segment breit. Augentrager konisch. Riissel walzenformig. Scheren kurzer als der Riissel. Finger ohne Ziihne. Palpen neungliedrig. Brutbeine zehngliedrig ohne eigentiimlich geformte Doruen oder Ziihne an den 4 letzen Gliedern. An den mannlichen Brutbeinen ist das 7. Glied sehr kurz, aber viel dicker als die andern 3 Endglieder. This genus was established for the reception of a remarkably fine species, L. striatum (Mobius), of which however only two examples were taken, and both of them immature. A species in the same collection described by Prof. Mobius as Colossendeis gibbosa appeared to me to be closely related, and an examination of the two species which I have been permitted to make fully confirmed this suspicion. The ' Discovery ' has brought from the Antarctic several species which are unquestionably very closely related. The ' Francais ' (2) lias also found two species. Two more were described some years ago by Dr. Pfeffer (24), from South Georgia, and placed by him in the genus Ammothea. That the genus Leionymphon is very closely related to Ammothea is beyond all question. To this latter genus not less than thirty species have been ascribed, but many of them present such peculiar characters that they cannot fairly be included. It is not possible here to revise the genus, but I have considered it desirable to modify Prof. Mobius' definition of the genus Leionymphon, and to give a list of those species which I consider should be included therein. LEIONYMPHON. Body more or less robust, with transverse ridges developed to a greater or less extent. The lateral processes widely separated or otherwise ; spurs rather than spines, or traces of them, occur on the lateral processes and first coxaa. The Proboscis is large, cylindrical or pyriforni. The Palps are nine-jointed, the last five joints being short. * "Xti'os glatt. Die 4 letzten Glieder Jcr Brutbeine sind nicht init eigentiimlich geformten Ziihnen oder Dornen besetzt." VOL. m. R 40 T. V. HODGSON. The Oviger is ten-jointed, without a terminal claw, the last four joints with an irregular series of special spines. In the male, the seventh joint bears a tuft of set;e, and the eighth and ninth joints are articulated at a considerable angle to the preceding joints. The Legs are long, tarsus very small, propodus armed proxiinally on the ventral margin with a scries of stout spines, claw rather large, and accompanied by two well-developed auxiliaries. The Genital apertures occur in the male on the two posterior pairs of legs ; in the female on all the legs. The species I would assign to this genus are :— L. striatum, Mobius, 1902. L. (jrande, Pfeffer, 1889 = Ammothea grandis, Pfeffer. = Ammothea charcoti, Bouvier. L. giVbosum,^S&sm&, 1902 = Colossendeis gibbosa, Mobius. L. minus, sp. nov. L. claKsii, Pfeffer, 1881) = Ammothea clausii, Pfeffer. L. australe, sp. nov. L. f/laciale, sp. nov. L. spinosttm, sp. nov. I have hesitated for some time as to the position of Ammothea magniceps (Thomson) from New Zealand (30). Mr. G. M. Thomson most kindly placed the whole of his collection at my disposal, but unfortunately it does not contain an adult male of this species, therefore the structure of the male oviger remains unknown. The transverse ridges of the trunk are prominent, but there is no trace whatever of the spurs so characteristic of Leionymphon. Under any circumstances, the species cannot be regarded as a true Ammothea. (Mr. Thomson is in error in describing the palp as with ten joints, there are only nine.) Be the true position of this species as it may, it exhibits a preliminary stage in the transition between the diminutive Ammothea and the large Leionymphon. The next step is indicated by L. clausii- and L. australe ; these two species are very much alike ; from these by L. minor, L. gibbosum, and L. (/randi* to L. ftfriiitiiDi. It would be difficult to give L. alaclalis and L. spinosum a position in a linear series. They probably diverge from L. striatum in a different direction to the others. KEY TO THE SPECIES. Body traversed by three prominent pyramidal ridges, spinose or setose : — Lateral processes close together — *Proboscis half as long as body, cylindrical. L. striatum. Proboscis little longer than body, cylindrical. L. grande. *Proboscis as long as body, conical. L. r/ibbosum. Proboscis shorter than body, slender, pyriform. L. minus. Lateral processes widely separated— Proboscis little shorter than body. L. i/lariale. Proboscis short, not half length of body. L. spinosum. Body traversed by three rounded ridges, smooth : — Abdomen vertical, base traversed by the last trunk articulation. L. clausii. Abdomen oblique, some distance behind the last trunk articulation. L. australe. * Known only from immature examples. PYCXOUONIDA. 4 1 LEIONYMPHON GRANDE. (Plate VI., fig. 1.) Ammothea grandis, Pfeffer (24), p. l::. Ammothea chairoft, Bouvicr (2), p. 295. Specific characters : — Body robust, with three prominent transverse ridges dorsally and veutrally. Proboscis cylindrical, very little longer than the body. Palp 9-joiuted, the last joint a little longer than any of the four preceding ones. Oviger 10-jointed, without a terminal claw, the last four joints with simple curved spines, which increase in size to the extremity of the last joint. The body is .stout, and with the abdomen, scarcely as loiig as the proboscis, being just less than 15mm. Its width across the second pair of lateral processes is 10mm. Its segmentation is complete, but concealed by a very strongly developed pyramidal ridge which lies along the posterior margin of the three anterior segments, aud the apex of which is raised considerably above the body level. These ridges have a very slight curvature forwards, which is most marked in the first. The lateral processes are not widely separated, the two anterior pairs are directed forwards, the first more than the other, and are quite close together ; the third pair is directed backwards slightly with a wider interval between it and the preceding pair ; the last pair is directed backwards at such an angle as to make the interval between the third and fourth pair very conspicuous. All have a swelling at the distal extremity, and this swelling gives the process an angular appearance. The Cephalon is short, expanded anteriorly, and at the base of the chelifori presents the same angular appearance as the lateral processes. A slight median groove divides its anterior margin. The Ocular tubercle lies in the middle ; it is stout, with a very slight curvature, rounded at the apex, and bearing four well-developed eyes. The Abdomen rises from the extremity of the trunk, but without trace of segmentation ; it is rather stout, slightly curved, and directed upwards. There is a median tubercle between the posterior transverse ridge and the abdomen. Dorsally the entire body is rendered scabrous by the presence of small spinous setfe ; between the body ridges however they are scarce. Ventrally the three transverse ridges of the dorsum are represented by three similar ridges, thinner and not produced to such a conspicuous point ; all are directed backwards to a varying degree, the first more so than the others. These ridges are continued on to the base of the lateral processes, which here do not present any trace of the angular enlargements so conspicuous dorsally. The spinous setae of the dorsum are not present. The Proboscis is stout and cylindrical, milv a trifle lunger than the body and abdomen together. It is articulated to the budy. and movable through a very considerable angle. The mouth is large and triangular. The distal extremity of the organ is deeply pigmented ; for nearly three-quarters of its length it displays six R 2 42 T. V. HODGSON. bands of a dark yellowish-brown colour ; it then abruptly changes colour, and tapers a little to its junction with the body. The Chelifori are rudimentary, and arise from the cephalou dorsal to the proboscis, and rather in advance of its origin. The scape is short and stout, slightly curved, and with the distal extremity oblique. Articulated to it is a mere knob which bears at its extremity a minute tubercle in a distinct socket, and on its outer border a small spine. The entire appendage is covered with minute spinous setse. The Palps are nine-jointed, and arise from the cephalon immediately below and external to the chelifori. The first joint is small, and the second is very nearly four times as long, the third is again small, and the fourth nearly twice as long as the second. The remaining five joints are together but little longer than the fourth, and differ but little in size ; the terminal one, however, is the longest of this series. The entire appendage is covered rather irregularly with the characteristic small spinous setse of the animal. They are not numerous on the proximal four joints, but on the remaining five they are rather longer and finer, as well as being a little more abundant. The Ovigers are ten-jointed, and arise ventrally at the angles formed by the first pair of lateral processes and the body. All the joints are small, the second and fourth being a little the longest (fig. la). The first joint is very small but stout, the second and fourth are the longest and sub-equal, the third is shorter and slightly curved. From the fourth the three following joints progressively decrease a little in length, the first three forming a curve in the natural position of the appendage. All these joints are stout, the three terminal ones becoming more and more slender ; the eighth joint, though more slender, has the same character as the preceding, the ninth is a little shorter, and the last one is the longest of the four terminals. The entire limb is covered, but not thickly, with small setse ; they are most numerous on the fourth, fifth, and sixth joints, on the latter of which they are conspicuous only on the outer side of its curvature. The remaining four joints form a curve in a contrary direction, and on the inner side of this curve is a row of stout curved setse, increasing in size and strength to the end of the terminal joint, where they form a conspicuous group. These spines are quite simple, and the last joint does not bear a claw, though it seems adapted for one. The Legs are stout but not of any excessive length, being something like 62mm. The second coxa is fully as long as the other two together, and the proportions of the remaining joints are as — 15 : 13 : 17 : 1 : 5. The first coxa is marked with a median dorsal and ventral line which separates the muscles moving the succeeding joint, the distal margin is tuberculated dorsally like the lateral processes, but only to a very slight extent ; the second coxa is conspicuously wider in diameter at its distal than at its proximal extremity. All three are covered with very small but stout setse. The femur is a stout joint, its distal extremity being raised dorsally into a slight angular ridge ; the entire joint is covered with the characteristic setse with the exception of a PYCNOGONIDA. 43 lateral band of some width, almost completely bare of them. On the two tibire the same arrangement of the setfe occurs, except that along the middle of the bare band there is a narrow baud of sette two or three wide. The distal fringes of the femur and first tibia are not conspicuous, but that of the second tibia is formed of stout spines chiefly on the ventral surface. The tarsus is a very small joint, and forms a cup-like socket for the propodus (fig. Ib); it is thickly covered with small spines, and its distal fringe is well developed, especially veutrally, where it is formed of very stout spines. The propodus is covered thickly with stout setae with only an irregular vestige of the bare band found on other joints ; it is slightly curved, and its ventral side bears proximally four or more very stout spines, of which the first is the smallest ; the rest of the margin is taken up with setas small, but larger than the average ; close to the terminal claw is a group of large setse, one of which at least is a rather prominent spine, The extremity of the joint is oblique, and forms a rounded spinose projection or heel beyond the origin of the stout claw, which, with its two powerful auxiliaries, arise from a common investment. The single adult specimen captured is a female, and the Genital apertures are conspicuous on the second coxa of each leg. Five smaller specimens were, however, taken at the same time and place, varying in size from 9 "5 mm. to 18 '5 mm. over all. These present several differences of no small importance. The proboscis differs slightly in form, being more tapering the smaller the specimen, and it is also more rigidly articulated to the body ; in none of them is it movable through so large an angle as in the adult. The chelifori are proportionally the same size as in the adult, but a perfect chela is developed. This is small and feeble, the fingers curved like a pair of callipers, and devoid of teeth. On the body the dorsal ridges are raised into a more definite median point, and the tubercles which give an angular appearance to the lateral processes and first coxae of the adult are now rather more prominent and carried on to other joints. The pre-abdominal tubercle is a very variable structure, and is sometimes prominent — in one case almost absent. The palps do not call for any fresh description, but the ovigers show several interesting stages in their development (figs. Ic-lf). In the smallest specimen only the merest vestige of such an appendage exists. In the next specimen four joints as such may be distinguished, the last one showing an indication of future segmentation. In another, six joints are fairly well established, the penultimate one showing traces of another division. In the largest of the immature specimens the oviger possesses the full number of ten joints, but they are very small, and the four terminal ones are only indicated and not clearly developed. Cape Wadworth, Coulman Island, 8-15 fathoms. Bottom : stones. Several adult specimens were taken by the ' Franeais ' off the west coast of Graham's Land, and one was taken by the ' Scotia.' The examination of Professor Pfeffer's Ammothea grandis from South Georgia has established the identity of this species beyond all question. 44 T. V. HODGSON. MINUS. (Plate VI., fig. 2.) Specific characters : — Body rather robust, with three prominent transverse ridges produced to a point in the uiid- dorsal line. Proboscis shorter than the body, slender, pyriform. Palp 9-jointed ; the terminal joint twice as long as any of the preceding four. Oviger 10-jointed. In the male the three terminal joints bear an irregular series of stout but simple spines. No terminal claws. The body is rather robust and the lateral processes are clearly but not very widely separated. It measures rather less than 5 mm. in length and less than 4 mm. in extreme width. The segmentation is distinct, and the articulations lie at the hinder part of the three transverse ridges which cross the body. These ridges are strongly developed, produced to a point in the middle line, and slightly curved backwards. They are equally prominent ventrally, but inflected backwards and not produced into a point. The lateral processes are stout, the two anterior being directed forwards at slightly different angles, the twTo posterior ones are similarly directed backwards ; each bears dorsally two distinct tubercular processes which are also to be found in a less prominent degree on the first coxae. The Cephalon is scarcely, if at all, expanded, and its centre is occupied by a very stout Ocular tubercle which is directed slightly forwards, and appearing, in certain aspects, to be enlarged near its extremity, which bears a very rudimentary spine. The four eyes are not particularly well developed. The Abdomen is short and stout, not separated from the trunk by an articulation ; it is directed obliquely upwards and does not extend as far backwards as the last pair of lateral processes. The Proboscis is pyriform, slender, and about two-thirds the length of the body, to which it is flexibly united. It shows indistinctly three pairs of longitudinal bands along the greater part of its length. The Chelifori are rudimentary ; the scape is well developed, slightly curved, and bears only a few small setae besides the rather prominent distal fringe. The chelae are reduced to a knob with the merest traces of fingers. The Palps are 9-jointed and rise at the side of the proboscis ; the first and third joints are quite short and subequal, the second and fourth are also subequal and about five times as long ; the four following are quite short and subequal, while the terminal one is ovoid and twice as long as any of the preceding four. The fourth joint bears a small distal fringe, but otherwise there are practically no setae on the first four joints ; the following four joints are very considerably dilated ventrally, and this enlargement bears a dense tuft of small stiff setae. The terminal joint is more extensively covered with setse, especially on its ventral side. The Ovigers are 10-jointed and rise ventrally just in front of the first lateral PYCNOGONIDA. -15 process (fig. 2a). The first joint is small and stout, the second is more than twice as long, stout and enlarged distally, the third is scarcely as long and has an oblique termination. These three joints form a curve in one direction, and the three following form a similar curve in another. The fourth and fifth joints are long and subequal, the sixth being about half the length of either ; its termination is rounded, the following joint being articulated at the side. All these joints are more or less plentifully setose ; the sette are very small, but their structure and arrangement call for no comment. The seventh and succeeding joints progressively decrease in length and stoutness as far as can be made out from the angle at which they lie, and they are all small. The seventh lies at right angles to the sixth, and near its distal and inner side it bears a dense tuft of long setae. The eighth joint is articulated at the side of the seventh and at right angles to it ; it also bears a small tuft of long setse near its distal extremity but on its outer side ; the following joint is similarly provided, but with fewer. The last three joints bear an irregular series, not a single row, of stout spines (fig. 2c) ; most of them occur on the terminal joint, but there are scarcely a dozen altogether. There is no terminal claw. The Oviger of the female is essentially different to this (fig. 2b). All the joints are smaller, the third conspicuously smaller than the preceding, and the fourth, though the longest of the appendage, is still quite short, and the remainder gradually and progressively decrease in length. Up to the sixth the joints remain stout, the rest are much more slender, and there is nothing noteworthy in their articulation, which is quite normal. The sixth joint is thickly covered on its outer side with minute setae, and up to this joint the setaa have been increasing in number. The terminal joint is unfortunately missing in the specimen examined, but the three preceding are almost devoid of any setae at all. The Legs measure about 28 mm. in length. The second coxa is scarcely the length of the other two together, the femur measures some 7 mm., the first tibia is the merest trifle shorter, the second a little longer, 7'5 mm., the tarsus and propodus together are about one-third the length of the second tibia. The second coxa bears a small but distinct tubercular enlargement just beyond the middle of its length dorsally, and in the male there is a similar tubercle dorsally near the extremity of the femur, with a o-landular aperture upon it. The entire limb is setose, but the setae arc very small ; no definite arrangement can be seen as far as the first tibia, up to this joint they are not numerous and only visible with difficulty. On the tibiae they become numerous ; on the first their arrangement is indistinct, on the second it is more readily made out, and consists of a dorsal and a ventral band of setne with another narrow band passing along the centre of a bare space laterally. The distal fringes are but poorly developed, the most conspicuous one being on the second tibia and chiefly ventral. The tarsus is a very small cuplike joint, densely setose on its longer and ventral margin. The propodus is slightly curved and dorsally projects considerably beyond the insertion of the large terminal claw and its strong auxiliaries. The joint is thickly covered with stout 46 T. V. HODGSON. setre on its ventral surface, and proximally there is a row of some four to six very strong spines ; dorsally the setae are similar, but not so thickly distributed nor so strong ; laterally also they occur, and there appears to be a narrow band devoid of setse, but this is not distinct. The terminal claw and its auxiliaries arise from a process on the ventral side of the prolongation alluded to above. The type of this species is an adult male bearing eggs, taken in Winter Quarters at a depth of 125 fm., 9 Feb., 1903. Another was found at a depth of 35 fin., 5 March, 1903. The ova are small and are carried in a large, rather irregular mass round the fourth and fifth joints of the oviger. The Genital apertures occur ventrally at the distal extremity of the second coxa of the two posterior legs. They are large, with tumid lips. Genital apertures of the female are on all the legs. A male and a female were also taken off Cape Wad worth, Coalman Island, in 8-15 fm., 15 Jan., 1902. These are smaller than the type. LBIONYMPHON AUSTRALE. (Plate VII., fig. 1.) Specific characters : — Body robust, with three low rounded transverse ridges; these ridges are more prominent ventrally. Abdomen directed obliquely upwards, and well behind posterior trunk articulation. Proboscis pyriform, little shorter than the body. Palp 9-jointed, the seventh and ninth being a little the longest of the five terminal joints. Oviger 10-jointed, without a terminal claw, the last four joints with an irregular series of denticulate spines. The body is robust and, without taking the lateral processes into consideration, broadest about the third process, from which it gradually narrows forwards. The Cephalon is but slightly expanded and the neck is not distinct. The entire body measures 9 mm. in length, of which 4 mm. are taken up by the proboscis ; the Abdomen does not enter into consideration, as in its natural position it is carried obliquely upwards, and does not extend beyond the last pair of lateral processes ; it is, however, l| mm. long. Segmentation is distinct, except so far as regards the abdomen, and occurs on a low ridge which crosses the body immediately behind the lateral processes. These ridges also occur ventrally and, being reflected backwards, give to each segment the appearance of being socketed into a recess. The lateral processes are not widely separated, but the intervals increase slightly from before, backwards ; all are provided at their distal extremities with two small spur-like processes ; these are dorsal. The Ocular tubercle is stout, moderately tall, rounded at the apex, and bears four well -developed eyes. The Proboscis is movably articulated to the body and pyriform in shape, its diameter increases for more than a third of its length, and then enlarges abruptly, and is marked by three double bands, presumably muscle bauds, transversely divided near the tip. The mouth is triangular, not large, but with thick lips. PYCNOGONIDA. 47 The Ckelifori are rudimentary and comprise a stout scape of one joint, which is slightly curved ; except for a distal fringe which is not conspicuous, the joint is not setose. The chelae in the adult are only represented by knobs, and these show the merest traces of two fingers. In younger specimens the chelae are developed and exhibit comparatively long curved fingers devoid of teeth. The Palps are nine-jointed and arise at the side of the proboscis. The first joint is short and stout, the proportions of the three following are as 5 : 1 : 4 ; the remaining five are all short and differ little in size, the first and third are sub-equal, the second and terminal are very little shorter but also sub-equal, the penultimate is the shortest ; the last joint is ovoid in shape, setose throughout, the setae more thickly distributed on its inner margin. The other four joints have slender bases and arc much enlarged and densely setose on the inner margin ; the outer margin is straight and bears a distal fringe. The preceding joints are also more or less setose, the short setae beginning near the distal extremity of the second joint and becoming fairly numerous on the fourth. The Ovigers are ten-jointed and arise ventro-laterally immediately in front of the first pair of lateral processes ; they differ in the two sexes. In the male (fig. la), the first joint is small and stout, and the proportions of the five following are as 4 : 2'3 : 4 : 4 : 2 ; the first of these, second of the appendage, is slightly curved ; the next is less so, but with the three following forms a large curve, the fifth joint being the only one that is distinctly curved itself. All these joints are setose, particularly on the outer side of the curvatures. The four remaining joints are short ; the seventh is articulated at the end of the sixth, but at the side, and makes nearly a right angle with it ; near its distal extremity it is provided with a dense tuft of long setae. The eighth joint is similarly articulated to the seventh, but in the opposite direction, and bears a smaller tuft of long setae distally ; the ninth is the shortest joint. The three terminal joints bear a small number, less than a dozen, of denticulate spines, most of which occur on the terminal joint. They are not in a single row, and consist of a slender shaft with seven .closely-set flat teeth on each side. The oviger of the female is quite different and the articulation of its joints is normal throughout (fig. Ib). The first and third joints are together equal to the second ; the fourth and fifth are sub-equal, and the longest on the appendage ; the sixth and seventh are a little shorter and sub-equal, the eighth and tenth are again shorter and sub-equal, and the ninth still shorter. Setae are scarce, and the sixth joint is the only one that can be described as setose. The denticulate spines occur on the four terminal joints, and are exactly like those of the male, but much more numerous, there being upwards of a dozen on each of the joints except the first of the series. With regard to the Legs, the second coxa is scarcely as long as the other two together ; the proportions of the three following joints are as 6'5 : 6 : 7'5 ; 48 T. V. HODGSON. these joints are subject to variation, but not of great moment, '5 mm. or there- abouts ; the tarsus is quite small and cup-shaped, the propodus rather more than a quarter the length of the second tibia. The entire limb is covered with short setae, but on the second tibia and the propodus there are longer ones interspersed among them. Throughout the entire limb there is a broad lateral band devoid of setae except for a narrow row of them along its centre ; dorsally and veiitrally the setse are abundant, particularly towards the extremity of the limb. The distal fringes are normal and inconspicuous, i.e., indistinct on the first coxa, ventral or chiefly so on the other two, complete on the femur ; on the two tibiae they are best developed ventrally, and become spinous, especially on the second ; the tarsus is covered with small spines or spinous setae ventrally, the propodus has a very prominent heel and bears a stout claw with two well-developed auxiliaries rather more than half its size. The heel bears numerous spinous setae, and at the proximal end of the joint on its ventral margin there are some half-dozen stout and prominent spines. The Genital apertures occur on the second coxae of all the legs in the female, but they can only be found on the two posterior legs of the male. The ova are small and numerous and are carried in a spherical packet round the fourth joint of the oviger. Several specimens of this species were taken in Winter Quarters at depths varying from 25 to 125 fms., the majority however coming from the latter depth. The specimens vary in age and size, but the species may be regarded as a variable one. While the general arrangement of the setse remains the same it is not so clear in the young examples. In these the setae are for the most part long and fine instead of short and comparatively stout ; the transition from the one form to the other is gradual, some of the adults retain a goodly proportion of the long setae among the others. A very few minute setae may be found on the body in some individuals, especially on the abdomen. In most individuals the summit of the ocular tubercle bears a very short spine instead of being rounded. In the young the chelae are fairly well developed, they are of moderate size, the fingers being quite smooth and resembling a pair of callipers. The spur-like tubercles on the lateral processes of the adult are, in the young, very prominent spines and frequently bifurcated ; similar spines occur on the cephalon. One specimen has the oviger not completely developed and in another the full number of joints is not yet differentiated. All the adults possess a glandular aperture of some kind on the dorsal surface of the second coxa just beyond the middle of its length. One individual has the second and third legs of the left side abnormally developed, probably new growths in reparation of injury ; one of these limbs does not extend beyond the extremity of the first tibia, the other is longer. This species very closely resembles L. cluusi Pfeffer, but may lie readily PYCNOGONIDA. 49 distinguished by the fact that in that species the abdomen is directed almost vertically upwards, and is situated so far forward that the posterior trunk segment passes over its base, a feature of, possibly, some morphological importance. LEIONYMPHON SPINOSUM. (Plate VII., fig. 2.) Specific characters : — Body stoutly built, with the transverse ridges not very strongly developed, but with a very prominent spur in the mid-dorsal line. The lateral processes are rather widely separated, and bear distally two stout recurved spurs ; smaller ones exist on the first coxae. Proboscis short, not half the length of the trunk. Palps '.1-jointed ; of the five terminals the seventh and ninth are a little longer than the others. Oviger 10-jointed, special spines not denticulate. The entire animal is heavily built, and covered with fine but short seta?. The lateral processes are rather widely separated, the intervals increasing posteriorly, two pairs of processes are directed more or less forward, the other two pairs backward. Each process bears dorsally at its distal extremity a pair of prominent recurved tubercular processes ; these are also distinct, though less prominent, on the first coxae. The body is crossed transversely by three ridges, but these do not extend on to the lateral processes as much as in the allied species. These ridges stand erect, but they are bevelled from behind in the middle line so as to form an acute point of some considerable elevation, and this gives them the appearance of being arched forward. The Cephalon is not very much expanded, and almost fills the interval between the first pair of lateral processes ; in front it bears a pair of tubercular processes directed outwards, one at the base of each of the chelifori. The Ocular tubercle is just behind the centre of the cephalon and is very stout, taller than any of the transverse ridges, and terminates in a cone above four well-developed eyes. The Abdomen is not separated from the body by an articulation ; it is of normal proportions, elongate, ovate and directed slightly upwards. The entire body is covered with short, fine setse, but they appear to be deficient between the ridges, and to some extent on the cephalon. Veutrally the transverse ridges are rounded, and the median spur much less prominent than dorsally ; the setae also are deficient. The length of the body is 13 mm., and its extreme width is 8 mm. The Proboscis is short and stout, being barely 5 mm in length, cylindrical, slightly swollen in the middle, and movably articulated to the body. The Chelifori are rudimentary, they lie close together above the proboscis and are more than half its length. The scape is half the length of the proboscis, very slightly enlarged distally and clothed with short setse ; the chelae are only knobs, also setose, and with but vestiges of the fingers. The Palps rise laterally below the chelifori and comprise nine joints (fig. 2a). The first joint is short and stout, the proportions of the various joints being : 1'5 : 4 : I : 3'5 : 1 : 1 : 1'3 : 1 : 1'5. The entire appendage is covered with fine setse which become numerous on the fourth joint ; on the four following joints they form a dense patch covering the 50 T. V. HODGSON. whole ventral surface, and extending dorsally in a very small degree on the first of these joints but progressively more and more as the extremity of the appendage is approached. The terminal joint is completely covered, but they are most abundant ventrally. The 0 vigors are ten -jointed and rise ventrally in the angle formed by the cephalou and the first lateral process (fig. 2b). The first six joints form the normal double curve and are all more or less covered with small setae on the outer part of the curvatures. The proportions of the various joints are : 1'5 : 3'25 :2:3:3:2:2:2:1'5:2. The last four joints are provided with a few large spinous setae forming, on three of the joints, a small irregular group ventrally near the distal extremity ; on the terminal one, which is much the most slender, they are scattered along its length, one of them taking the place of the terminal claw. The Legs are not all the same size, the third pair being the longest and the first the shortest, their respective lengths being approximately 30 mm., 35 mm., 39 mm., 37 '5 mm. The third leg of the right side has been measured. Of the three coxae the second is longer than either of the other two, the three together attain a length of 8 mm., and the proportions of the other joints are as 9'25 : 9 : 8 : 3'5, the last figure representing the tarsus and propodus together. The entire appendage is densely clothed with rather short but fine setae having no special arrangement, except that on the femur and first tibia they are not so numerous laterally. The tarsus is small, cuplike, densely setose, but with no strong spines. The propodus is slightly curved, densely setose, and with an oblique termination to the joint, but the process from which the large terminal claw and its two moderate-sized auxiliaries arise projects beyond the joint itself. The ventral margin of the propodus is spinose but varies greatly. In the best instance there is a series of eight spines, the first four are small and then they increase in size rapidly to the last, which is very large. These occupy the proximal half of the joint. Then follows another series of six of nearly uniform size and not so large as the biggest of the previous series. This second series occupies the remainder of the joint and are disposed radially. In other cases the first series is not so well developed and the second is deficient. The single specimen of this species is an adult female, the Genital apertures are found near the middle of the second coxse of all the legs. Taken in 300 fathoms off the Barrier. Bottom : mud. January 27, 1902. LEIONYMPHON GLACIALE. (Plate VII. , fig. 3.) Specific characters : — Body well built, with three very prominent transverse ridges produced to a point in the mid-dorsal line. Lateral processes rather widely separated, and with the stumps of spur-like processes distally. Proboscis large, but shorter than the body, pyriform. Palps 9-jointed, the five terminals being sub-equal in size. Oviger 10-jointed (not mature). This is a large and comparatively slender species. PYCNOGONIDA. 51 The Body is well built with the lateral processes rather widely separated, and traversed by three very prominent pyramidal ridges which conceal the segmentation. These ridges are directed backwards to a very slight extent and excavated posteriorly ; it is in the hollow thus formed that the segmental divisions may be seen. Three ridges are equally prominent ventrally, but they are not produced to a median point. The Cephalon is not very much expanded, and a neck is not noticeable. The Ocular tubercle is stout, not as tall as any of the three transverse ridges, and bears four well-developed eyes, above which it terminates in a short cone. The Abdomen is rather long, directed obliquely upwards, not separated from the trunk by an articulation, and terminating in a blunt point. The cephalon bears a small blunt tubercle at its anterior margin on the outer side of the base of the chelifori, a pair of similar tubercles occur dorsally at the extremity of the lateral processes ; smaller ones also on the first coxse with traces of them on the second. The length of the body is 12 mm., its extreme width is 7 mm. The entire body is scabrous, a feature most distinctly noticeable on the transverse ridges and the abdomen. The Proboscis is large, rather pyriform in shape, and measuring 10 mm. in length. It is niovably articulated to the body on a large base, and widens slowly for one-third of its length where it is very slightly constricted ; it is then enlarged again, and tapering very slightly, ends in a rather broad round point, the triangular mouth being of moderate dimensions. The proboscis is smooth, and its distal two- thirds are marked by three pairs of longitudinal bauds, transversely divided near the tip. The Chelifori are rudimentary and lie close together above the proboscis. The scape is short, slightly curved and enlarged distally ; the chelae are well developed, as long as the scape, one half of their length is taken up by a bulbous palm ; the fingers are slender, quite smooth and much curved, but those of the two appendages are not exactly alike. With the exception of the fingers the entire appendage is scabrous. The Palps arise laterally just outside the chelifori, and comprise nine joints (fig. 3a). The first is short and stout, the proportions of the second and fourth are as 8 to 11, the third being but little longer than the first; the remaining five are short and sub-equal, the middle one and the last being a trifle the longest, together they scarcely equal the length of the fourth. The fourth joint possesses a prominent tubercle with a glandular opening at two-thirds of its length. The entire appendage is more or less plentifully clothed with very minute spinous setae ; these however are only conspicuous on the ventral margin of the five terminal joints and at the end of the terminal one. The Oviger is ten-jointed and rises ventrally immediately in front of the first lateral process, and appears to be that of a female (fig. 3b). It is not fully developed. The first joint is short and stout, the two following are twice as long and sub-equal, the third having the usual oblique termination. These three joints form a natural 52 T. V. HODGSON. curve in one direction, and the three following curve in another. Measured in their extreme length the proportions of the various joints of the appendage are : 3:6:6:8: 775 : 7 : 4 : 4 : 2'5 : 4. The third and following joints are all more or less covered with very short stout setae on the outer side of their curvature ; these setae are most con- spicuous on the fourth, fifth, and sixth joints, on the last of which they are also lateral. The last four joints each bear a small number of stout but simple spines, 4:8:7:6, not arranged in a single row. The last joint tapers to a blunt point, and is without a terminal claw, a small group of these spines taking its place. The Legs attain a length of about 55 mm. Of the three coxae the second is twice the length of the other two, the proportions of the remaining joints being 13'5 : 12 : 16:4, the last figure representing the tarsus and propodus together. The coxse are densely clothed with very minute setse, but on the femur they are much larger, though still small, and more conspicuous. They are arranged as a dorsal and a ventral band, separated laterally by a considerable interval, along the centre of which is a narrow band of similar setse. This arrangement is continued along the tibias but it is not so distinct on the second. The distal fringes are quite normal and incon- spicuous. The tarsus is a very small cup-like joint, covered with spiuous setae ventrally, with a few prominent ones distally. The propodus is uniformly covered with small spinous setae, but ventrally there is a row of stout spines running the whole length of the joint. These spines are very irregular ; beginning from the proximal end the first three or four rapidly increase to large dimensions, the rest are very irregular in size, but none are so large as the last of the proximal series. The joint terminates obliquely, the dorsal projection is not large ; the terminal claw is stout, and its two auxiliaries are quite half as long, arising together from a process of the oblique termination. The single specimen of this species is immature, and was taken in Winter Quarters at a depth of 125 fathoms. AUSTRODECUS. Body stout, and distinctly segmented, with lateral processes close together. Ocular tubercle anteriorly situated, long, with four well-developed eyes. Proboscis immovably articulated to the trunk and ventral in position ; long, tapering, slender. Chelifori absent. Palps 6-jointed. Oviger G-jointed ? no terminal claw. Legs short ; genital apertures on the second coxae of all the legs in female. (Male as yet unknown.) 1 have considered the affinities of this and of the succeeding genus in the intro- duction to this memoir. PYCNOUONiDA. 53 ACSTRODECUS GLACIALS. (Plate VIII. , fig. 1.) Specific characters : — Body stout, segmented, with lateral processes close together. Proboscis long, tapering and curved near the extremity. Chelifori absent. Palps G-jointed ; terminal joint articulated to one side of the penultimate. Ovigers G-jointed ? Legs short, first coxa} armed dorsally with two spurs. Abdomen long and slender. This is a diminutive species ; the entire animal does not cover a space 8 mm. square. The trunk is stout and distinctly segmented ; the lateral processes are not widely separated, but as they are rather short and tapering, the intervals at their distal extremities are very pronounced. The first coxae, which are the largest, all bear dorsally a pair of stout tubercular spines which are very prominent. Each of the four segments of the trunk bears a stout tubercle of some elevation in the middle line, and close to its posterior border. The Cephalou is scarcely expanded, and almost fills the interval between the first pair of lateral processes and their first coxae. Anteriorly it bears a very long Ocular tubercle which is directed obliquely forwards, flask-shaped and truncated at its extremity, on the upper surface of which, in a compact group, are four very well-developed eyes. From the truncated end of the trunk the Abdomen projects horizontally ; it is rather long and not separated by an articulation. On the ventral surface of the trunk a slightly raised baud passes transversely between the first three pairs of lateral processes, with the last pair the baud is interrupted in the middle line. The Proboscis is long and of a peculiar shape, not unlike the snout of a weevil beetle. It is movably articulated to the body, and for about one-third of its length it is not disproportionately slender, then it tapers rather rapidly to a long and very slender structure, curved downwards near the tip. It is quite smooth and presents an annular appearance which is less distinct proximally. The Chelifori are quite absent. The Palps are six -jointed and arise above but well to the side of the proboscis (fig. lb). The first joint is short and very stout, the second is long and extends beyond the extremity of the ocular tubercle. The third is very short and its distal limit indistinct. The fourth joint is rather more than half the length of the second. The second joint bears the stumps of several spinous setae along its length ; on the fourth joint a similar number of curved spinous set;e occur, and these increase in size to the distal extremity of the joint, which also bears a few finer setae and a small distal fringe. The last two are quite small and rather densely clothed with small setae. The last one is articulated to one side, and not at the end, of the penultimate, and the setae occur mainly on the outer side. 54 T. V. HODGSON. The Ovigers arise ventro-laterally, close to the angle formed by the cephalon and the first lateral process. They are extremely small, and it is open to question whether they are mature or not. As the removal of one of these appendages involves serious risk to the only specimen, it cannot be very satisfactorily described. Not less than six joints can be distinguished, the first three of which are very small. A small body- process from which the appendage arises may be an additional joint. The terminal joint is the longest, it is rounded at the extremity and does not carry any trace of a claw, nor are setae of any kind discernible. With regard to the Legs, the first coxa has already been alluded to as the largest of the three, the other two are very little if any shorter, and the second is dilated distally. It is difficult to get the limb in one plane for measurement, and the joints appear subject to some variation. The proportion of the joints appears to be 3'5 : 3 : 2'5 : '5 : 2'5. The femur is stout, and the two following joints decrease in calibre. The limb bears a very few scattered setae, most numerous on the second tibia. The tarsus is very small and cup-like, with two or three spinous setse ventrally ; the propodus is proportionately long, slightly curved, and bearing a few setse. On its ventral margin it carries a row of setse, but there is nothing very distinctive about them. The claw is short and stout, and is accompanied by two slender auxiliaries. The only example of this peculiar species is a female, and the Genital apertures are found in the middle of the second coxae of all the legs. Taken by the dredge in Winter Quarters before the ship was frozen in. Ten fathoms or less. AUSTRORAPTUS. Body with spurs on the lateral processes and first COXEB. Segmentation very imperfect. Proboscis stout at the base, terminating in a point. Chelifori rudimentary. Palps 6-jointed. Ovigers 10-jointed, without terminal claw or denticulate spines. Legs comparatively long, terminal claw with two auxiliaries. AUSTRORAPTUS POLARIS. (Plate VIII. , fig. 2.) Specific characters : — Body rather stout, with promineut spurs on the lateral processes and the first coxte. Proboscis half the length of the trunk, pointed. Palp 6-jointed, the terminal joint is twice as long as its predecessor, and articulated at an angle to it. 0 vigor 10-jointed, without terminal claw or denticulate spines. Legs long, terminal claw with two small auxiliaries. The body is rather robust, with long lateral processes which arise close together and diverge considerably. These are provided dorsally with a pair of stout tubercular spines which exist also on the first coxse, where they are greatly exaggerated. PYCNOGONIDA. 55 The Cephalon is considerably enlarged, and almost completely fills the interval between the first pair of lateral processes. The Ocular tubercle is stout and tall, terminating in a cone above the four well-developed eyes. It lies well to the front of the cephalon. The Abdomen is long, cylindrical, almost horizontal, and not separated from the body by an articulation. The extreme length and breadth of the trunk is as G to 5 '5, the abdomen increasing the length to 7'5. The articulation of the trunk is indistinct, that separating the last segment being non-existent. The entire body appears to be perfectly smooth. The Proboscis is about half the length of the trunk ; it lies underneath the cephalon, directed obliquely downwards ; it is stout and cylindrical for the greater part of its length, tapering off to a sharp cone. It is movably articulated to the trunk. The Chelifori are rudimentary ; the scape is well developed, stout, not setose, a little longer than the cephalon ; the chelae are reduced to a knob, inclined inwards at an angle of about 45°, with only the merest traces of fingers. The Palp is short and only possesses six joints: It rises close to the proboscis, below and outside the chelifori (fig. 2a). The first joint is short and stout, and the second is three times as long ; the third is again very small and, forming an elbow, is shorter on one side than the other. The fourth is the longest joint, though but little longer than the second, the only setae visible forming a small distal fringe. The following joint is characteristic; it is small, and its inner margin is just half the length of its outer border ; this outer border is well supplied with setae distally. To the oblique termination of this joint the sixth and last joint- is articulated. It is twice the extreme length of its predecessor and richly setose on its outer border and extremity. The Oviger is 10-jointed and rises ventro-laterally at the angle formed by the first lateral process with the cephalon (fig. 2b). It is a short appendage ; the first three joints are short and stout, the second and third are sub-equal in length, but not in diameter, and nearly twice the length of the first ; the two following are the longest joints, the fifth being a trifle longer than the fourth and sparingly setose ; the sixth is short, the seventh is longer, and the three terminal ones progressively decrease in length and diameter, the last one being very small. The last five joints are sparingly supplied with setae. On the terminal joint there are three long and stout ones. There is no terminal claw nor are there any special spines. The ovigcr of the male has not been removed, but does not differ essentially. The Legs measure some 18 mm. in length. The second coxa is fully as long as the other two together, and is much enlarged distally. The femur and first tibia are sub-equal in length, and the second tibia is a very little longer ; the tarsus and propodus together are rather more than one-third the length of the second tibia. The tarsus is very small and cup-like, richly setose ventrally, the setae being stout, one VOL. III. T 56 T. V. HODGSON. especially so. The propodus is very slightly curved and covered ventrally with short spinous setae, with, proximally, a row of four stout spines. Dorsally the setae are small and scanty. The terminal claw is large, more than half the length of the joint, and accompanied by two small auxiliaries. These claws arise on a process from the oblique termination of the joint. The extreme end does not project much beyond, and is supplied with numerous spinous setae. The rest -of the limb, coxae, femur, and tibiae are fairly well covered with very small setae ; their precise distribution is not easy to observe, but they appear to be deficient laterally ; they are most abundant on the second tibia. The lateral line is well marked on the three largest joints. The specimen above described is an adult female, and shows conspicuous Genital apertures on a swelling at the extremity of the second coxa of all the legs. An adult male shows smaller apertures on the three posterior legs only. The female was taken in 100 fathoms, rough ground, off the Barrier, in Lat. 78° 16' 14" S., Long. 197° 41' 47" E. The male was taken in 300 fathoms, mud, off the Barrier, in Lat. 71° 25' 40" S., Long. 1 85° 39' 06" E. EHYNCHOTHORAX. Rhinchothorax, 0. G. Costa, Microdoride Mediterranea (1861), p. 7. I have not seen Costa's original description of this genus or its attendant species. In the 'Challenger' Report (14) it is included by Dr. P. P. C. Hoek in his list of the then known species of Pycuogonida, and at the same time condemned as being insufficiently described. It is not a little remarkable that out of ten species then recorded from the Mediterranean only one is described in Dr. Dohrn's monograph (8). Zoologists are indebted to that author for the careful and full descriptions of the Pycnogonida therein recorded. The genus and species of Rldnchothorax mediterraneus Costa a,re fully described, and differ in many particulars from the original description. Dr. Dohrn states— That the Chelifori are absent. That the Palp is eight-jointed, but that fusion has taken place, reducing the number of distinct joints to five. Five distinct joints are figured, the limits of the remainder being obscure. That the Ovigers ar.e eleven-jointed. In both figures, however, only ten joints are shown. 1 have no hesitation in placing the species described below in the genus Rhyueho- thorax as defined by Dr. Dohrn for these reasons : the general aspect of the animal is similar ; the proboscis is cleft at its extremity ; though the palps arc only five-jointed, the feebly-developed extremity seems to indicate some reduction is taking place ; and the ovigers are ten-jointed, and the exact counterpart of those figured by Dr. Dohru. PYCNOGONIDA. RHYNCHOTHORAX AUSTRALIS. (Plate VIII., fig. 3.) Specific characters : — Body very robust, with lateral processes quite close together, and with median tubercles on the segments. Chelifori absent. Palps 5-jointed, the second joint with a very strongly developed spur dorsally. Ovigers 10-jointed, with a terminal claw, the last four joints with a couple of spines on an enlarged base. Legs short, terminal claw with two small auxiliaries. Body very robust, with the lateral processes short and quite close together, widest across the first lateral process, and about half the breadth across the last. The posterior articulation of the trunk is deficient, but immediately in front of where it should be, as on the preceding segments, is a stout median tubercle, bluntly pointed, and very slightly inclined forwards. The Cephalon is expanded, but very short. The Ocular tubercle, which is stout, projects forwards and upwards over the base of the proboscis. It bears four well- developed eyes, the posterior pair being a little the larger, and terminates above them in a short cone. Measured from the anterior margin of the ocular tubercle, the cephalon is half the length of the first segment of the trunk. The Abdomen is long, about as long as the two combined segments from which it originates. Proboscis is stout, conical, a little longer than the first trunk segment. A conspicuous slit marks the mouth as the animal lies in its normal position. Chelifori, no trace. Palps. These appendages only comprise five joints, and are very curiously modified (fig. 3a). Each rises at the side of the proboscis and extends but little beyond it. The first joint is short and stout, the second is the longest of the appendage ; its dorsal extremity is prolonged forwards and upwards as a stout spur. The third joint is about half as long as the shaft of the second, it is enlarged distally, a stout dorsal tubercle bearing a tuft of setae; a few other setae are more scattered. The fourth joint is small and setose, while the fifth, which is also richly setose, is reduced to a mere button. The Oviger is very slender, ten-jointed, and rises ventro-laterally at the neck (fig. 3a). The first three joints are short, and progressively lengthen, but only to a slight degree. The fourth is nearly as long as the three together. The fifth is shorter, but swollen distally. The sixth is shorter still. No setae are discernible on any of these joints. Of the four terminals the first three are sub-equal in length, but their dorsal surfaces become more and more curved. Ventrally, also, there arc prominent projections which bear the denticulate spines. The terminal joint is very broad, and a little longer than the others ; its dorsal outline is very much curved, and veutrally a large swelling occupies almost the whole surface ; one small spine is T 2 58 T. V. HODGSON. all that is visible. A prominent claw terminates the appendage. The denticulate spines are few in number, two on each of the first three joints. They are worn, and all that remains is a slender shaft of uniform diameter with three terminal teeth, of which the middle one is the largest. The Legs are short. The three coxae are short and stout, the second is by a very little the longest, but the first has nearly twice its diameter ; it also bears a tubercle smaller than, but similar to, those borne on the middle line of the trunk. The femur is stout, and not so long as the three coxae together, but the remainder of the appendage is much more slender. The proportions of the two tibiae are as 3 to 2, the tarsus and propodus together being as long as the second tibia. The tarsus is a very small joint, its ventral surface being covered with minute spiuous setae. The propodus, which is curved, has a row of them along its ventral margin, separated by rather wide intervals ; several setse are scattered dorsally. The terminal claw is stout and is accompanied by two slender auxiliaries about one-third its size. A few setse are scattered on other parts of the appendage, but they do not form a prominent feature. The Genital apertures are distinct on the second coxae of the last pair of legs only, and this joint is much swollen in consequence. This species, of which there is only a single specimen, was found by Mr. Kirk- patrick on a sponge. Winter Quarters, at a depth of 178 fm., 7 Aug., 1902. COLOSSENDEIS. Body ovoid or elongate, with the lateral processes close together or widely separated, as a general rule without segmentation. Cephalon small. Eyes well developed or absent. Proboscis very large, often much longer than the body, and movably articulated to it. Chelifori very rarely present, rudimentary. Palps very long, 10-jointed, third and fifth joints the longest, more or less setose. Ovigers very long, 10-jointed, fourth and sixth joints the longest, the last four joints bearing several rows of spines usually dentate. A terminal claw. Legs without auxiliary claws ; the three coxal joints short. Abdomen of moderate dimensions, movably articulated to the trunk, sub-clavate. Genital apertures on the second coxa of all the legs. I defined this genus in comparison with Decolopoda in the Zoologischer Anzeiger (13), retaining as far as possible the words of Jarzynsky. Certain characters made use of by Professor G. 0. Sars (25) have been incorporated, since his definition has become inapplicable in certain important features. No less than eighteen species and two varieties have been described. Through the generosity of Professor E. L. Bouvier I have been permitted to examine the collection of Colossendeids made by the ' Travailleur ' and ' Talisman,' the description of which is not yet published. The identity of these species with the known species, or otherwise, has not yet been fully established, but four new species from the Antarctic Regions are now described. PYCNOGONIDA. 59 COLOSSENDEIS AUSTRALIS. (Plate IX., fig. 1 ; Plate X., figs. 1 and 2.) Specific characters : — Body stoufc, with lateral processes widely separated, minutely scabrous, the spines being arranged in distinct rows on the appendages. Proboscis enormous, bottle-shaped, more than half as long again as the body. Eyes, four, well developed. Palp 10-jointed, the eighth and ninth joints equal, the tenth longer. Claw of legs less than half the length of the propodus. Under a lens the entire animal exhibits a beautifully mottled appearance, which, to a greater or less extent, appears to be characteristic of the genus. The Body shows the faintest traces of segmentation ; the cephalon is short and only very little expanded, and the first pair of lateral processes is placed close against it. The Ocular tubercle is situated in the middle of this area and is stout, with four well-developed eyes, two anterior and two posterior, the latter smaller than the others. The Proboscis is of much greater diameter than the body, to which it is movably articulated ; throughout the greater part of its length it is curved downwards ; the mouth is very large. The organ is covered with minute spines, which seem to have, to some extent at least, an indistinct linear arrangement ; the difficulty of making out their precise arrangement is accentuated by a growth of polyzoa. The Abdomen is of moderate dimensions and somewhat clavate. The ten-jointed Palp arises ventro-laterally, as close as possible to the proboscis. The two first joints are very short, and the third is rather more than twice the length of the fifth ; the fourth is small ; the sixth is barely one-third the length of the fifth, and the seventh is about half as long again as its predecessor ; the eighth and ninth are shorter and sub-equal ; the terminal one is absent from one side and injured on the other, but in the other specimen available it is a little longer. The lateral line appears along the greater part of the appendage. The entire limb is spinose, beginning with the third joint, and the minute spines are arranged longitudinally in rows as far as the end of the fifth joint, which, with the two preceding, bears a more or less complete whorl of spines at its distal extremity. Beyond the fifth joint the spines become stiff setse rather than spines; they are larger and more abundant and irregular, besides being aggregated on the ventral and inner side in the natural position of the limb. The Ovigers are very long and, as characteristic of the genus, 10-jointed (fig. la). They arise from a small body-process immediately behind the palps, but nearer the middle line. The first three joints are small, the fourth and sixth are the longest and sub-equal, the fifth being about a quarter their size. The last four are sub-equal, and the appendage terminates in a small claw. The lateral line is distinctly marked. The entire limb is spinous. A few minute spines exist on the first three joints, beyond these they are arranged more or less clearly in lines and are more numerous. Then- is also a fringe of small spines on the outer margin of the distal extremity of each 60 T. V. HODGSON. joint, but these are either inconspicuous or absent on the four terminal joints. With regard to the characteristic groups of spines on the four terminal joints, there are four rows on the three proximal joints and three only on the terminal joint. In both specimens the spines are so much worn as to give but a feeble idea of their true character (Plate X., figs. 1 and 2). The large size of the sockets in which they are planted is remarkable. The most ventral row, that which lies nearest the sea bottom in the natural position of the animal, comprises a small number, less than a dozen, of large stout spines. The second row, which in this species is not separated from the first by any conspicuous interval, contains approximately double the number of smaller spines ; the sockets of this row are sometimes crowded together, and the spines are smallest and most crowded at the proximal end of the joint, and are also deflected from a straight line by the articulation of the succeeding joint. Two other rows follow, but these have not the mathematical regularity of the former, nor are they so much deflected ; they are reduced in number, but not in size. In structure the large spines appear to consist of a stout base almost circular in section and composed of a strong chitinous investment having a protoplasmic core ; the spine tapers to a blunt point much worn, but with enough left to indicate a flattened blade at the extremity. The Leg attains a length of 115 mm. The three coxae may be regarded as sub-equal in size, and short. The two tibiae are the longest joints and sub-equal, except in the first leg, where the second tibia is a trifle shorter than the first. The femur is a little shorter, and the tarsus less than half the length of any of the three preceding joints ; the propodus is just over half the length of the tarsus. On the first coxa there is dorsally and ventrally a median line of reddish colour, which appears to indicate the presence of a slight groove. On the second coxa the lateral line begins on each side of the joint, and passes to the extremity of the limb. The three coxse are minutely scabrous and possess a small fringe of minute spines at their distal margins. The remaining joints are more or less covered with these fine spines, which become a little more conspicuous as the extremity of the appendage is reached. Six rows are fairly well defined throughout the limb, a median dorsal, a median ventral, and two lateral, one on each side the so-called lateral line. The distal extremity of each joint bears a fringe of spines on the inside of the bend, largest and most conspicuous on the second tibia. The terminal claw is small, less than half the. length of the propodus. The Genital apertures occur on the second coxa of all the legs in both sexes, us shown in figs. Ib and Ic. The above description has been prepared from an example taken in deep water. Another from shallow water presents certain differences : first, it is more spiuose, especially the proboscis and the limbs ; on the legs four additional irregular rows of spines may be distinguished between the six described for the deep-water specimen, I \vo of these are dorsal and two ventral : and secondly, in the comparative length of I'YCNOGONIDA. 61 certain joints. The third joint of the palp is distinctly less than twice the length of the fifth, and the fourth joint of the ovigerous leg is a little longer than the sixth. The nearest ally of this species seems to be C. proboscidea, Sabine, from which, however, it may be instantly recognised by the wider intervals between the lateral processes and the presence of well-developed eyes. Two specimens of this species were taken, one off Cape Wadworth, Coulman Island, 8-15 fm.; bottom : stones ; the second off Mounts Erebus and Terror, 500 fm.; bottom : stones. This latter specimen is the carrier of some half-dozen cirripedes of the genus Scalpellum. COLOSSENDEIS GLACIALIS. (Plate IX., fig. 2 ; Plate X., figs. 3 and 4.) Specific characters :— Body apparently smooth, with lateral processes widely separated, and four well-developed eyes. Proboscis not quite so long as the trunk, slightly dilated about the middle, and covered with short spinous set«3. Palps, three terminal joints sub-equal arid densely setose, with wide and deep constrictions at the joints. The body is rather stouter proportionally than the last two species, and though apparently smooth, a lens reveals a median row of extremely minute setse. The Cephalon is not expanded beyond the average width of the body. The Ocular tubercle is stout, and bears four eyes, the anterior pair larger than the posterior ; the portion above the eyes is acutely pointed, but this feature is variable in size. The setous character of the proboscis is not always easily discernible ; in one specimen it is prominent, in others less so, even when not concealed by a growth of polyzoa. It can hardly be said that these setse are arranged in any definite manner, but in places they give the impression of ill-defined rows. The Abdomen is short a.nd articulated to the trunk. The Proboscis is as defined among the specific characters and fiexibly united to the trunk. The Palps arise on the ventral side of ^ the proboscis (fig. 2) ; the first joint is rather more prominent than usual, and is readily seen from the dorsal surface. The second joint is shorter, the third is considerably the longest of the appendage, the fourth is (juite short, and the fifth is approximately two-thirds the length of the third ; this joint has a faint constriction at about two-thirds of its length. The following joint is short, the next a little longer, the three terminal joints being short and sub-equal. The extremity of the palp has a peculiar appearance, owing to the seventh, eighth, and ninth joints, and to a less extent the sixth, having their distal extremities rounded oft' like the shoulders of a wide-mouthed bottle, so that cadi joint seems balanced on a narrow base. The entire appendage is beset with stiff set;r, almost spinous in character. On the third joint they are short, somewhat sparselv distributed, and appear to be arranged in rows. A whorl of stouter setse (spines ?) 62 T. V. HODGSON. surround the distal extremity of this joint and the next ; beyond this the setae are so thickly distributed that it is scarcely possible to make out any definite arrangement. On the fifth joint some of the setae are distinctly longer than the majority, and from this joint the setae on the inner side of the appendage, in its natural position, are much the longest. The Ovigers arise immediately behind the palps on a conspicuous body-process close to the middle line (fig. 2a). The first three joints are small, and bear spinoua setae of small size. The fourth and sixth are very long and sub-equal, the fifth being not more than a quarter of their length. The four terminal joints are sub-equal in length, but decrease in stoutness. The entire appendage is setose. On the fourth joint the setae are small and arranged in rows, and on the outer margin, at about two-thirds of its length, a small but distinct, rounded protuberance occurs. On the succeeding joints the setae or spines, whichever they may be called, are more thickly distributed. The characteristic spines of the four terminal joints present very slight differences from the two preceding species. On the ventral side of the limb in its natural position are two rows of these spines separated by a conspicuous interval ; the more ventral of these two rows consists of a few large spines, the other contains approximately double the number of smaller spines. Dorsally, and separated by an interval, are two rows of smaller spines, which are not, however, arranged with such precision as the others. Close examination reveals the fact that the intervals between the rows of spines are more apparent than real, this effect being due to the set of the first two rows and the third group or double row ; the second row is deflected at the extremity by the articulation of the succeeding joint. The spines do not present any special peculiarities, being more like true spines than in the other species here described. They are somewhat curved or falciform (Plate X., fig. 3). The terminal claw is of moderate dimensions, rather slender, but with a stout base ; in most of the specimens the stout base is all that is left. All four terminal joints are dorsally covered with short spinous setae set in sockets (Plate X., fig. 4). In this species they are much more numerous than in the other three. Concerning the Legs, the first coxa has a slightly greater diameter than the others, and bears the dorsal and ventral mark so characteristic of the genus. The other two coxae are nearly equal in length and all are minutely spinose. The Genital apertures occur on the second coxae of all the limbs, and the lateral line beginning on that joint is conspicuous to the end of the limb. The first tibia is the longest joint of the limb, the femur is very little shorter, the second tibia approximates to three-quarters the length of the first, and the tarsus to very nearly half its length ; the propodus is shorter than the tarsus by nearly a third, and the claw is less than half the length of the propodus. The entire limb is covered with minute setae, which, along the dorsal surface at any rate, have a distinct linear arrangement ; ventrally this becomes indistinct from the second tibia onwards. The distal extremity of each joint, including the coxae, is more or less .completely girdled with spines, minute up to PYCNOGONIDA. (I:! the extremity of the femur, arid most numerous dorsally ; on the first tibia they increase in size ventrally, and still more so on the second tibia ; on the tarsus and propodus the ventral setse are comparatively long and conspicuous. The specimen from which the above description was taken seemed to be an exceptionally spinose individual. Seven specimens were obtained, and in the other six all the features described above can be seen, though to a less degree, when not concealed by a growth of polyzoa. Winter Quarters, 12 to 25 fathoms. COLOSSENDEIS FRIGIDA. (Plate IX., fig. 3 ; Plate X., figs. 5 and 6.) Specific characters : — Body smooth, with lateral processes widely separated. Four well-developed eyes. Proboscis approximately twice the length of the trunk, dilated about the centre and quite smooth. Palps, 10-jointed ; eighth joint half the size of the two terminals, which are sub-equal. Ovigers, with a group of four or five irregular rows of special spines in addition to the two primary rows. Claws of legs about half the size of the propodus. This last character, together with the spines and terminal claws on the ovigers, readily separate this species from C. megalonyx, to which it appears very closely related. A considerable amount of latitude must be allowed on the proportions of the joints of the various appendages as a guide to specific discrimination. Thus the proboscis varies in length from 11 mm. to rather more than 21 mm., and the trunk to the base of the abdomen, from rather less than 6 mm. to rather more than 1 1 mm., but the longest proboscis does not coincide with the longest body. The same sort of variation occurs throughout. There is no trace of segmentation in the trunk, and the Proboscis is articulated to it, hence the variation of the angle to which it may be inclined. The Ocular tubercle is stout, sharply conical above the eyes, which are well developed and four in number. The Abdomen is quite small and articulated to the trunk. The Palps are ten-jointed. The third joint is much longer than the fifth, which reaches almost to the extremity of the proboscis. The fourth joint is very small, and the seventh is slightly longer than the sixth ; the eighth is quite short, the two terminals being twice its size and sub-equal. Towards the extremity of the fifth joint very minute setae make their appearance, and on the rest of the appendage they are scattered in more or less definite rows. Ovigers : These appendages arise close to the middle line behind the palps (fig. ;3). The first three joints are very small, the fourth and sixth long and sub-equal, the sixth as a rule extending beyond the proboscis. The fifth joint is about half the length of the sixth. The four terminal joints are sub-equal, and the claw has a peculiar appearance, as if the inner margin had been bevelled off at a very acute VOL. III. U 04 T. V. HODGSON. angle. In its perfect condition it is rather long and slender, especially the distal half. Something like one-half of this slender portion, at the tip of the claw, is flattened dorso-ventrally to form a sort of protective shield to a thin membranous fold lying like a knife-edge on the under surface of the claw throughout its distal half (fig. 3a). The claw is covered with very minute hairs. The characteristic spines are very numerous, and are arranged in two sharply defined lines followed by a closely arranged group in which five rows can be distinguished. A distinct interval separates the first two rows from each other and from the group referred to above. The spines of the first row are long, slender, lanceolate in shape, and set as closely together as possible (Plate X., figs. 5 and 6). Those of the second row are approxi- mately double in number, shorter and more spathulate, their essential structure being the same. They have a fairly stout base tapering to the centre, where it becomes a flat blade, the entire margin of which is provided with minute teeth visible under a one-inch objective. In the group of spines there are five rows arranged in an imbricate manner and as the spines of these rows alternate fairly regularly oblique rows of eight spines may be distinguished in the broadest part of the group, In structure they resemble those of the second row. Setae are sparsely distributed over the appendage and though very minute they are not difficult to distinguish. The legs of the numerous specimens average between 58 mm. and 106 mm. in length ; the proportions of the joints do not, however, vary greatly. The first coxa bears a reddish line marking a very shallow groove dorsally and ventrally ; the lateral line begins on each side of the second coxa, and is continued to the extremity of the limb. The three coxae are sub-equal. The femur is the largest joint of the limb as a rule, the other joints decreasing in size to the extremity. The claw is about half the length of the propodus. The Genital apertures occur on the second coxa of all the limbs of both sexes. The legs are apparently quite smooth, even to the touch, but close examination shows faint traces of rows of setae. In some of the larger specimens these are a little more conspicuous. Specimens of this species were taken in Winter Quarters in depths varying from 5 to 178 fathoms, and the name is derived from the fact that two of them had to be taken to the ship dry, a distance of nearly two miles, at a temperature of -50° Fahr. They suffered in consequence. Another specimen taken in 300 fathoms ; bottom, mud ; off the Barrier, 27.1. '02, is referred to this species. COLOSSENDEIS RUGOSA. (Plate IX., fig. 4 ; Plate X., fig. 7.) Specific characters :— Proboscis half as long again us the body, slender, dilated about the middle, with a median row of curved spines dorsally along the proximal half. liuily smooth, with lateral processes widely separated, and, with the first coxa, dilating distally. Palps LO-jointed, the eighth very short ; the ninth rather more than twice its length ; the terminal one a little larger still. Legs provided with rows of spines, claw large. PYCNOGONIDA. 65 This species in general appearance very closely resembles the last, but may 1)0 readily distinguished by its spiny character and the features quoted above. The Body is quite smooth, the ccphalon short and without any constriction indicating a neck. The Ocular tubercle is stout, with four well-developed eyes, the anterior pair being larger than tthe posterior pair. Above the eyes the tubercle is acutely conical. The Proboscis is half as long as the body as indicated in the specific characters, and besides the median row of spines there is a lateral row of a few, widely separated. The proboscis is movably articulated to the body, and obtusely pointed distally. The Abdomen is small, somewhat clavate, but presenting no special feature. The Palps arise on the ventral side of the body, as close as possible to the proboscis. They arise on a process of the body which is usually regarded as the first joint, but which has always appeared to me to be doubtful whether it is a real joint or not. In this particular species it is definitely a body-process and not a true joint. The succeeding joint, here as elsewhere called the second, is very short, a mere ring- like segment. The third is considerably the longest joint of the appendage, slender and furnished with a few prominent curved spines ; the fourth is quite small ; the fifth is two-thirds the length of the third ; and a short distance from the distal extremity there is a distinct constriction as though there had been a joint there and it had fused ; the sixtli is short, and the seventh is about half as long again ; the eighth joint is very short, scarcely half the length of the sixth ; the ninth is fully twice the length of the eighth, and the terminal one a little longer, rounded at the extremity. From, and including the fourth joint, the entire organ is covered with minute spines, too plentifully distributed to assert any regular disposition. The Ovigers arise laterally from two body-processes close to the middle line and immediately behind the proboscis (fig. 4). The first three joints are very small and sub-equal in length ; the fourth and sixth are very long and sub-equal, the fifth being about one-third of their length; of the four terminal joints, the proximal is the largest. The claw is of moderate dimensions. The entire appendage is covered with very minute spines, which become numerous from the fourth joint, and appear to be v. SATIS, G. 0. Pycnogonidea. Zoology of tlie Norwegian North Atlantic Expedition. 1891. iT,. SCIIIMKKWITSCH, AV. Sur les Pantopodes, recueillis par M. Ic lieutenant G. Cherchia pendant le voyage de la Corvette ' Vettor Pisaui ' en 1882-85. Atti della R. Accad. dci Lincei, Mem. (4) VI., pp. 329-347, 1 pi. 1889. 27. SnmiKKWiTSCH, "W. Conipte-reudu sur les Pantopodes. Reports on dredging operations .... U.S. Fish Comm. S.S. 'Albatross,' during 1-891. Bull. Mus. Comp. Zool., Vol. XXV., 189:!, pp. 27-43, 2 pi. 28. ScimiKihviTscir, AV. Ueber die Periodizitilt in dem System der Pantopoda. Zool. Anz. Bd. XXX., 190(1, pp. 1-22. 29. STEBBIXR, T. R. R. The Nobodies : A Seafaring Family. Knowledge, \rol. 25, 1902, chap. 4, pp. 185-9. 30. THOMSON, G. M. On the New Zealand Pycnogonida, with Descriptions of New Species. Trans. N.Z. lust., Wellington, Vol. XVI., 1*84, pp. 242-8, pi. 11-10. 31. AViLSON, E. B. The Pycnogonida of New England and Adjacent AVaters. Rep. U.S. Fish Comm. for 1878, pt. VI., 1880, pp. 461-501',, pis. 1-7. 32. AViLsox, E. B. Report on the Pycnogonida. 1,'cpnrts on the Results of Dredging .... during 1880 by U.S. Coast Survey S.S. 'Blake.' Bull. Mus. Comp. Zool., Harvard, Vol. VIII., 1881, pp. 239-250, pis. 1-5. PYCNOGONIDA. G9 EXPLANATION OF THE PLATES. PLATE I. Fie. 1.— Phoxiehilns australis. 9 x 2. 2. — Pseudopallene australis. 9 x 3. 2a. — Oviger, five terminal joints. 9 x 20. 2b. — Denticulate spine from tenth joint, x 880. 3. — Pseudopallene cornigera. 9- Oviger, five terminal joints. 9 x 20. 3a. — Denticulate spine from eighth joint. X 530. 4. — Pallenopsis hiemalis. 9 X 3. 4a. — Oviger, six terminal joints, x 27. PLATE II. Fn;. 1. — Pallenopsis villosa. 9 x 3. la.— Chela, x 18. Ib. — Oviger. x 10. 2. — Pallenopsis pilosa. 9 Hock. Oviger, five joints, terminal one missing, x 22. 3. — Palk'uopsis hiemalis. 9 • Terminal joints of leg. X 12. 3a. — Specimen from Cape AVaihvorth. Terminal joints of legs, x 12. PLATE III. Fir,. 1. — Xymphon hiemale. . .\mmothea icilsoni; 3. Anoplodactylus neglectus, 2. .1 iirtphdattylus petwlatus, 2. Ascorhynchus gltiber, 3. Austrodecus gloriole, 3, 53. Austroraptus polaris, 3, 54. Chcetonymphon awtrale, 2, 32. Chcetonymphon anstrale, var. austrinorum, 2, 35. Ohoetonymphon biarticulafum, 2, 28. Clmtonymphon brevicaudatum, 2. Chcetonymphon mendosum, 2, 30. ClMtonymphon villosum, 2, 2G. Colossendeis anstralis, 3, 59. Colossendeisfriijida, 3, 03. Colossendeis gigas, 3. Colossendei* f/if/as lei>tnrhynchus, 3. Colossendeis glacialis, 3, 61. Colossendeis gracilis, 3. Colossendeis leptorhynchus, 3. Colossendeis mer/alonyx, 3. Colossendeis robitsto, 3. Colossendeis ru/josa, 3, C4. ('urdijJochfle turqueti, it. fii'i-nlopoda antarcticir, :i. Decolopoda australis, 1, 3. Leionymphon australe, 3, 4G. Leionymplio/i, dausii, 3. Leionymphon gibboswn, 2. Leionymjition glacial c, 3, 50. Leionymphon grande, 2, 41. Leionymphon minus, 2, 44. Leionymphon spinosum, 3, 49. Leionymphon striatt/in, 2. Nymphon adareanum, 2, 23. Nymph on antarctitum, 2. Nymphon bracliyrhynrhum, 2. Nymphon frirjidum, 2, 25. Nymphon fuscum, 2. Nymphon gracile, 2. Nymphon gracilipes, 2. Nymphon, hamatwn, 2. Nymphon hiemale, 2, 20. Nymphon lanare, 2, 22. Nymphon meridionals, 2. Pallene dimorpha, 2. Pallenopsis Jluminensis, 2 . Pallenopsis glabra, 2, 11. Pallenopsis hiemalis, 2, 17. Pall&nopsis patagonica, 2, 20. Pallenopsis pilosa, 2, 15. Pallenopsis villosa, 2, 13. Pentanymphon antarcticu.m, 1, 2, 36. Phoxichilus australis, 2, 5. Pswdopallem australis, 2, 1<). Pseudopallene corniyera, 2, 7. Pymogonum maf/ellanicum, 2. Pycnogonum magnirostre, 2. Rliynchothora.r australis, 1, 3, 57. Tanystyltim cl/ierchice, 3. Tanystylum do/trnii, 3. Tanijstylum stijligerum, 3. Plal 2b \ Lb Plat Antarctic (Discovery) Exp. Plate III. li. 3b 2 a Nymphon. 1. N. hiemale. 3. N. aclaT?eanum. 2.N. lanare. 4. ]ST. fpigidum. WeEt.lJev.- Antarctic (Discovery) Exp. Plate IV. Chaetonymphon . articulatum. West,Newman de: . . . Id If le Antarctic (Discovery) Exp Plate VIII. West.Newmar. Q>. 1. Austpodecus glaciale. 2. Austroraptus polaris. 3. Rhynch.otho.pax austpalis. Antard > Exp. 3 a 1. !.W. Sexton, ad. ji Colossendeis. 2. C. gla^ 3. C osa. tactic (Discovery) Exp. Plate X. 1 xlOO 2 jflOO 12 *63O 13 15 iSIS Figs 1-7 E.W.Sexton del. Figs 8-15 West,Newman del. Figsl&2. Colossendeih I. C.rugosa. . 8. Nymphon hiemale. Tig. 9. N. . :ymphc. • ACAEI. IIALACAEID.'E (ACARIENS MARINS). Par LE DR. E. L. TRODESSART, Professeur au Museum d'Histoire Naturelle de Paris, Membre Correspondaut de la Zoological Society of London. Avec 1 planclie d'aprfes les dessins de G. NEUMANN, Professeur a 1'Ecole Vete'rinaire de Toulouse. INTRODUCTION. EN terminant 1'e'tude des Acariens rapportes du Pole Antarctique par 1'expe'dition de la ' Belgica,' 1'auteur de ces lignes disait : " II est regrettable qu'aucune espece d'Halacaridse ne se soit rencontre'e au cours des dragages ope're's dans ces regions. Nous savoiis par les materiaux rapportes par Pouchet a la suite du voyage de la ' Manche,' et par ceux plus abondants encore, qui out ete recueillis par S. A. le Prince de Monaco, pendant la croisiere de la ' Princesse Alice,' sur les cotes du Spitzberg, que les Acariens marins sont nombreux et d'especes variees dans les mers arctiques. J'ai peine a croire qu'il n'en soit pas de meme dans les mers antarctiques. . . ."* Cette lacune se trouve aujourd'hui comblee. Les naturalistes de la ' Discovery ' ont rapportes deux Ilalacaridse, dragues au large de Granite Harbour. Tous deux appartieunent a une scule et meme espece, tres interessante, puisqu'elle se retrouve au Pole arctiquc. II est prol table que Ton en decouvrira d'autres par la suite. La presence, dans les mers autarctiques, d'unc espece ^Ilalacaridse, constituant tout au plus une sous-espece d'un type deja counu dans les mers arctiques (Halacarus [Leptospathifi] Albert i Trt.~), souleve une fois de plus la question de la liipolaritc. dcx faunes. Je n'ai pas 1'intention de revenir ici sur cette question, qui semble avoir ete suffisamment discutee par Joubin,* Kcohler,f Topsent,| Dollo,§ Gieslireclit^[ et d'autres, ct 1 Resultats du voyage du S.Y. ' Belgica ' (Zoologie, Acariens), 1903, p. 10. * Resultats du Voyage de la ' Belgica ' (Mollusques), 1903, p. 71 ; du meme, Bull. Mus. Oceanogvaphique de Monaco, Cours d'Oceanograpkie, 1905, p. 31, et suiv. f Resultats, ete. (Echinides), 1901, p. 36. f Resultats, etc. (Spongiaires), 1901, p. 8. § Resultats, etc. (Poissons), 1904, p. 191, ct suiv. f Resultats, etc. (Copepodes), 1902, p. 7. x 2 2 DR. E. L. TROUESSART. que Ton peut considerer comme parfaitemente resolue, dans 1'etat actuel de la science. On peut la resumer aiusi : La theorie de la bipolarite est dementie par les faits : toutes les especes communes aux deux poles sont des especes cosmopolites, qui se sont propagees peu-a-peu, a travers les epoques geologiques, soit par la coutiuuite des continents ou le transport accidentel (especes terrestres), soit par les courants ou le fond des oceans (especes marines). En definitive, la bipolarite n'existe pas. II serait trop long de citer ici toutes les especes communes aux deux poles : je me contenterai d'en donner quelques exemples :— Parrni les Gephyriens, Spengel cite Priapulus caudatus, Lamarck. Parmi les Mollusques, Joubin indique Janthina rotundata. Parmi les Copepodes, Giesbrecht enumere les six especes suivantes : Onccea conifera, 0. notopus, Microstella atlantica, Oit/iona similis, Pseud ocalanus pygmceus, Harpacticus ckelifer. Parmi les Acariens terrestres, j'ai moi-meme indique Rhagidia (ou Nb'rneria) gigas. Parmi les Spongiaires, Topseut signale Leucosolenia lamarcki, Halickondria panicea, Dendoryx incrustans. Or, toutes ces especes sont cosmopolites. Bien que Halacarus alberti n'ait encore ete rencontre que dans les deux mers polaires, on peut predire qu'il se retrouvera ailleurs. D'apres ce que nous savous de la distribution des animaux marins, il est infiniment probable que cette interessante espece existe dans plasieurs stations intermediates, et quelle est cosmopolite ou subcosmopolite. Le fait qu'elle vit, dans les mers arctiques, a une certaine profondeur (entre 48 et 430 m.), confirmc cette maniere de voir. On sait, en effet, que si la temperature du fond descend dans les mers polaires a — 3°, elle ne s'eleve pas dans les mers tropicales au-dessus de +2°, et 1'ou peut conside'rer cette difference de 5° conirne insignifiante, lorsqu'il s'agit d'animaux vivants toute 1'annee dans des eaux froides. DESCRIPTION DE L'ESPECE ET DE SA SOUS-ESPECE. Le sous-genre Leptospathis Trt., auquel appartient cette espece, semble assez distinct d' Halacarus pour constituer un bon genre, et non plus une simple section subge'uerique. L'allongement du rostre, la forme de rhypostorne, 1'absence de piquant aux palpes, la disposition de la cuirasse, la gracilite des pattes, etc., ont fourni a Lohmann1 des raracU-re.s diili'Tcutiels pour son " Chevreuxi-Gruppe," qui correspond a notre S.-G. Leptospathis. La forme du rostre, et surtout la gracilite de I'hypostonie, qui iudiquent une difference notable dans le genre de nourriture, suffiseut a caracteriser ce genre. 1 Lohmann, Die Halacarinen dor Plankton Expedition, 1893, p. 58 (Plankton Expedition der Humboldt-Stiftung). ACARI. 3 LEPTOSPATHIS. Leptopsalis Trt., Comptes Remlus, cvii. (1*88), p. 755 (non Leptosalis Thorell, 1882). CJmi'reuxi-Gni(ipe Lohmaun, Halacarinen Plankton Exp., 1893, p. 68. Leptospathis, Trt. Rev. Biol. Nord., vi. (1804), p. 174. Caracteres. — Rostre grele et allonge ; hypostome long et grele, plus etroit a la base ou dans sa partie mediane, spatuliforme (et nou triangulaire, commc cbez Halacarus proprement clit). Type : Halacarus chevreuxi Trouessart. Le genre renferme les especes suivantes : 1. Leptospathis chevreuxi, Trt. 2. ,, nationalis, Lohm. 3. ,, liispida, Lohm. 4. ,, panopae, Lohm. 5. ,, hypertrophica, Lohm. G. ,, thaleia, Lohm. 7. „ alberti, Trt. Voici la diagnose de cette derniere espece, telle que je 1'ai clonnee en 19021. LEPTOSPATHIS ALBERTI TYPICA. " Cette grande espece est bien caracterisee par la forme de ses pattes. La cuirasse est mince et peu developpe'e, depourvue de cretes et de lamelles. Le tronc est ovale, un peu lobe par 1'insertion des pattes, avec 1'anus terminal. La plaque de 1'epistome est coupe'e carrement en avant, laissant le rostre a decouvert; les plaques oculaires sont subovales ; la plaque notogastrique est grande, ovale ; la plaque sternale tres dt'-veloppee, subtrapt-zoidale, etroite en arriere ; les plaques coxales tres larges, se rejoio-uent presque, en-dessous ; la plaque ventrale est petite, ronde, occupee presqu' entieremeut par le cadre gniital, arrondi. Toutes les plaques sont siruplement granuleuses, sans sculpture. Le rostre est conforme comme chez //. (L.) chevreuxi. Les pattes sont longues, a articles cylindriques, avec le tarse fortement recourbe en dedans, surtout a la 4C paire, et complfetement depourvu de gouttiere ougueale ; la piece mediane des grifFes se termine par un appendice bidente enorme. Les grift'es sont presque droites jusqu'a la dent accessoire, et ne portent qu'un peigne court occupant le milieu de la branche droite, a dents souvent usees on brisecs. Le 3e article des pattes est un peu renfle ; le 4e est fortement echaucre a sa base interne. (Dimensions : royez plus loin.) Dix specimens, males, femelles et nymphes. " Cette belle espece, la plus grande du sous-genre Leptospathis, est dediee a S. A. S. Albert ler, Prince Regnant de IMonaco." La sous-espece des mers antarctiques depasse encore en dimensions le type du Nord : nous la decrirons sous le nom suivant : 1 Trouessart, Bull. Soc. Zool. dc France, 1902, pp. 07, 68. 4 DTI. E. L. TROUESSART. LEPTOSPATHIS ALBERTI ANTARCTICA. Tms semblable au premier abord au type, mais en differant par sa taille plus o-rande et des proportions un peu difierentes, comme 1'indique le tableau suivant : Dimensions: L. Albert! typica. L. Albert! antarctica Tronc avec le rostre Tronc sans le rostre Rostre (longueur du) .... 1100 /x 900 200 780 1200 ,«. 1000 200 890 4e 720 780 3= 7GO 800 4e 800 900 450 530 Largeur du 3" article (lc paire) . ler et 2e articles de la le paire . 3e 80 120 200 60 120 250 4e 100 120 5<= 200 250 GC 150 150 N.B. — Ces dimensions varient un peu d'un individu a 1'autre. La comparaisou de ces chiffres montre que la sous-espece antarctique differe du type arctiquc par : 1° une taille un peu superieure ; 2° des pattes relativement plus longues et plus greles (notamment le 3e article de la le paire) ; 3° des proportions uu peu difterentes des pattes : ainsi, tandis que les ler, 2e et 6e articles de la le paire sont sensiblement egaux dans les deux formes, le 4e et surtout le 3e et le 5e montrent unc difference notable. Cette patte s'est done allongee surtout dans sa partie moyenne. DESCRIPTION DE LEPTOSPATHIS ALBERTI ANTARCTICA. Tronc. — Ovoide, largcment arrondi en avant ; le bord du camerostome presque droit transversalement, conii^ue en arriere, oil le tubercule anal forme un petit cone tronquu nettemeut distinct ; les flancs portent une forte echancrure au uiveau dc 1'inscrtion de la 2e paire de pattes, uue autre lieaucoup moins marquee a Tinsertion dc la 4° paire. /''"•«' dor sale : plaque de IV-pistorne plus large que longue, arrondie en demi-cercle en arrii're, son bord posterieur depassant un peu le uiveau de la 2e paire. Plaques lars irr^guliferement triangulaires, a bords arrondis, saillantes sur leur bord antero- * Avant la compression dans la preparation, Aprts compression, on trouve 000 et 600 /j environ. ACARI. 5 extcrne, qui porte deux leutilles oculaires. Plaque notogastriquc eu ovalc allonge", largement separee des autres, ne couvrant quo le milieu de la region, son bord postericur atteignant la base du tubercule anal. Face vent-rale: plaque sternale large, s'etendant lateralement jusqu'a la base des deux premieres paircs do pattes, son bord anterieur fortcment (-chancre en demi-cerele par 1'ouverture du camerostome, arrondie en arriere, et ue depassant pas la 2e paire de pattes. Plaque veutrale courte et peu large, mais se prolongeant sous le cone anal et presqu'entierement occupee par le cadre genital, qui est grand, arrondi, un peu ovalaire chez la femelle ; plus large, circulaire, chez le male. Chez la femelle, il porte six paires de poils inseres en-dedans du cadre ; chez le male il presente une double couronne de poils. Plaques coxales grandes, triaugulaires. Teguments tres finement plisses dans 1'intervalle des plaques ct portant, sur les flancs, des poils assez forts, savoir : un en avant de la plaque oculaire ; trois en avant de la 3° pairc de pattes ; deux en avant de la 4e ; un a la base du cone anal. Rostre. — A base hemispherique formaut calotte a la face dorsale, plus large que longue. Palpcs deux fois plus longs que la base, et depassant 1'hypostome de la longueur du dernier article ; presentant la forme caracteristique du G. Leptospathis, c'est-a-dire paralleles, a 3e article faiblemeut fusiforme, plus long que la moitie du palpe tout entier, le 4e trois fois plus court, le 5e et dernier un peu plus long, conique avec une petite pointe grele. Un poil rigide, long, et grele, dirige en avant a 1'extrernite interne du 3e article. Pattes. — Decroissant de longueur dans 1'ordre suivant ; 4e, le, 3°, 2e. - - lere paire : accolee au rostre, longue et grele (voyez les dimensions au tableau, page 43) ; les deux premiers articles courts, piriformes, le 3e allonge, faiblement renfle a son cxtremite ; le 4e assez court ; le 5e aussi long que le 3e ; le Ge (tarse) plus grele, un peu recourbe en dedans, sans echancrure ongueale, termine par des griffes longues, faiblement recourbees, ne portant de peigne que dans la partie mediane (ce peigne a 8 a 13 dents au plus). Piece mediane des griffes grande et forte, bidentee. Une touffe de cirrhes en-dessous de 1'extremite du tarse. Les poils que portent les pattes sont tous greles. --2e paire: semblable a la le, mais plus courte et un peu plus grele ; le 3e article, notamment, et le 5e sont manifestement plus courts qu'a la le paire. - - 3e paire : inseree un peu en arriere du milieu du tronc ; plus longue que la 2e, le tarse plus allonge. - - 4C paire : inseree tres en arriere, la plus longue de toutes, le tarse plus fortement recourbe en dedans, le 5e article portant sur son bord interne trois poils a base en chandelier, c'est-a-dire inse'res sur une petite saillie en forme de bobeche. La piece mediane du tarse beaucoup plus forte qu'a la ] e paire. Differences sexuelles. — La femelle ne differe du male que par la forme de 1'organe genital, la disposition et le petit nombre des poils qui 1'cntourent. Couleur. — Cette sous-espece est d'uu brun plus fonce (|uc le type du Norcl, ce qui pent tenir au genre de nourriture. Dimensions, — (Voyez le tableau, page 43.) 6 DR. E. L. TROUESSART. Nymphes. — De forme elliptique on naviculaire, les pattes relativement plus courtes, surtout celles de la 4e paire (d'apres le type du Nord). LEGENDE DBS FIGUEES. PLANCHE. FIG. 1. Lrptospathis alberti antarctica, Trt., adulte ""-' partie ; Mollusques, IP. 1 1:;. U8:!.V1S4::.) The species was represented by numerous specimens. They agreed with typical ln:ni/it, i-ii in almost every one of such diagnostic features as they had retained, the exceptions being that the anterior fin appeared to eitend slightly further forward than is usually the case (due possibly to imperfect preservation), and that the first (newest) jaw hardly showed the usual ridge and bay just below the tip ; the extent to which * The latest papers on Chaetognatha, summarising the distribution and literature of the group, are : " Biscayan Plankton collected during a cruise of H.M.S ' Research,' 1900, Fart III. — The Chaetognatha"; Transactions of the Linniean Society, 2nd Serii--*. Xool., Vol. X., pp. 55-87; and " Reports of the ' Siboga ' Expedition. Mono- graph XXI., The Chaetognatha" (Leiden, 1906). VOL. in. Y G. HERBERT FOWLER. this latter is developed, however, varies much in specimens from other localities. There seems no reason to regard these two points as sufficiently important to justify the separation of Antarctic specimens from D'Orbigny's species. Formulae, based on thirty-four specimens :— 75 13 7-8 4-5 8-9 55 15-18 7 4-5 7-9 51 ? 8-9 5 7 50 •?14 8 7 7 47 ' 14-17 6-8 4-5 7-9 43 13-15 7-8 3-5 5-7 39 15 8-9 4 6-7 38 15 8 5 6 34 15 8 3 5-6 33 18 7-8 4-5 6-7 31 ? 9 4 7 30 16 8-9 4-5 7 29 16-17 7-9 4-5 4-7 28 19-21 7-9 4 5-6 27 18 9 3 3-4 26 19 8-10 3-4 4-6 24 16-20 8-9 4 4-5 23 22 10-12 3-4 5 21 21 10 4 3 19 21 7-9 2 3 17 20 '.) 3 2 16 [ca.] ? 7 4 5 15 23 8-9 3 3 SAGITTA SKRRATO-DKNTATA. Sat/it/a serrato-dentata, Krohn, Arrhiv fiir Naturgeschichte xix. (185S), p. 272. As will lie shown below, this is not a truly Antarctic form. It appeared to be male-ripe at about 12 mm. of total length ; no really female-ripe specimens occurred. Formulae, based on 8 observations :— 13 27 7 6 10 12 33 7 5-6 8-11 1 1 36 7 4-5 9-10 10 40 7 4 6 9 ? 7-8 4 7 fHAETOGNATHA. KROHNIA HAMATA. itta liamata, Moebius, Zoologisclie Ergebuisse der [' Pommerania '] Nurdseefahrt : Venues. Jabres- bericbt cler Commission zur wissenschaftlichen Untersuchnng der Deiitselieu JMeeiv, .hilii-^niij; II., III. (1875), p. 158 ; pi. iii.. fig. 13-1H. Quite typical specimens of this species were captured, sometimes in large numbers, but the majority were small and immature specimens, under 15 mm. Formula?, based on 21 specimens :— 31 26 21 c. 20 19 17 c. 15 14 11 9 '2 4 '23 18-28 23-29 26 25 27 30 7-8 8-9 6-9 8 9 7-9 7-8 19-20 15 12-23 13 14-16 6-11 6-10 4 5-6 4 The occurrences of these species at the various stations are presented below in tabular form. Date. Position. Hole. Drjitll (fin.). Sagitta hexaptura. Sa^itta serratoden- tata. Kruhnia haimita. Temperature C . Oct. I'.l, 1'Jiil . . . 4o li-'S., 32 27' E. 0 1 20 12^4 to 9" 4 Oct. 22, 1001 . . . 15 00' S., 40° 57' E. — 0 1 9 4' 4 Oct. 23, 1901 . . . 15 os'S.. U 47' E. — o 10 . — 4' 4 Nov. 5, 1901 . . . is 44' 8., 100° 16'E. — II 11 — 5° 3 to 3 1 Nov. 11, 1901. . . 51 20' S.. ll'i; 23' E. — 0 •> 1 1 r, Nov. 21,1901. . . .M; 31' s.. i5i; ID' E. — 0 1 — 1 1 Nov. 22, 1901. . . 56°31'S., lot: 19'E. — o 11 — 43 :; i; Nov. 2:!. 1902. . . 77: -19' S.. n;u no' E. 4 8 1 — — -1 9 Dec. 1, 1902 . . . . . 1 7 1 — — -l :> Dec. s, 1902 . . . 4 G 1 — — -i°e Dec. 14, 1902 . . . 4 6 1 . — . — -i i; M;ir. 21, 190:'.. . . . . 4 0 1 — — -] 9 Mar. 25, 19o:!. . . 4 5 1 — . — -1 9 Mar. 27. 190:;. . . 8 10 1 — . — -1°9 Mav :.. I9n:l . . . . . 8 10 •>) — . — -1 9 May (!, 1903 . . . 1 5 1 — 1 - 1 9 May 9, 190:; . . . . . 4 5 3 — — -1°9 Miy I:'.. 1903 . . . 8 10 2 — — -1°9 May 1C, 19o3 . 4 5 1 — 1 -1°9 May 29. 19(i3 . . . . . 4 5 3 • — — - 1 9 June 1, 11(03 . . . 8 10 5 • — 1 -1 9 June 2s, L908. . . 8 10 — — 3 -L' 0 July 13, 1903 . . . 8 10 2 — 3 - 2° 0 Aug. 13, 19o; . . . 8 10 1 — 2 -1 9 Aug. 21, lllo: . . . s 10 1 — 6 -1°8 Am;. 27. 19o: . . . . . 8 10 1 — 8 -1° 8 Sept. 9. 190:; . . . 8 lltlll. — — 1 -1 s Sept. IS, I!Kt3. . . s 10 1 — — -! s Nov. 2. 1903 . . . 12 10 — — •> -1 s June 21, 19o|. . . 5G"12'S., 13G ].s'\V. — 10 3 — 60 3 0 June 21. 19o |. . . 58'49'S., 124 ts'\V. — 5 3 — 159 :-2 7 June 25, 19ol. . . 59°19'S., 120° 24' W. — 0 1 — 71 .. ., June 2S. 1904. . . 59°':U'S., KM; L's'AV. — 5 •> — 90 2 2 July 1, 1904 . . . 55°44'S., 95"! 3' W. — 5 3 — 61 5 3 Y 2 I G. HERBERT FOWLER. II.— THE COLLECTION OF H.M.S. 'CHALLENGER' IN ANTARCTIC AND SUBANTARCT1C WATERS. Some six years ago Sir John Murray, K.C.B., kindly sent to me the Chaetognatha collected by H.M.S. ' Challenger ' in 1873-1876. Captured at a date when methods of preservation (especially of plankton) had not been so carefully studied as of later years, and having lain for thirty years in alcohol, the specimens are, naturally enough, by no means in a condition to allow of a general report on the collection. So far, however, as could safely be done, I have attempted to identify the more characteristic species taken in nine hauls at the surface, which lay either in the cruise to the Antarctic or towards the subantarctic Patagonian region. These nine were the only hauls available in what may be termed the critical latitudes. They were studied mainly with the idea of finding approximately the northern limit of K. hamata at the surface, and the southern limit of S. serratodentata, the former being bipolar in the strictest sense, the latter being believed to be tropical, temperate, and subpolar only. They appropriately supplement the collection of the ' Discovery.' A considerable number of the specimens were in a hopeless condition ; only those are listed here of the identification of which the writer felt reasonably certain. As to the records of K. li i'c,' S., 9:1 44' E. n 5 9 — — — 154/5 Fub. 21, 1874 . (14 27' S., 9n 4s' E. -0 :: 1 — 5 i 153 Feb. 14, 1*74 . <;:• 42' S.. 79 49' E. -1"G 18 — 1 •» f> G. HERBERT FOWLER. III.— DISTRIBUTION. The occurrence of these species in really polar waters is of considerable interest. The record of hroltnia liamata as a truly " bipolar " species is thus completed; it ranges from 81° 30' N. (Romer and Schaudiun) to 77° 49' 8. ; it is both epiplanktonic and mesoplanktonic at high latitudes with low surface temperatures, but in tropical and warm temperate seas is known only from the colder strata of the mesoplankton. While, horizontally speaking, it appears to be cosmopolitan, and is fairly eury thermal, it has not been recorded definitively from a higher temperature than 12 '7° Cent. (' Challenger' Collection). As to Sagitta hexaptera, the captures of both ' Discovery ' and ' Challenger ' complete its record as a " pantothermal " species, that is to say, one living at practically every known sea-temperature, from about 29° C. to — 2° C. ; and as a truly cosmopolitan species, ranging from Spitsbergen in the north to the ' Discovery's ' winter quarters in the south, and from every sea from which Chaetognatha have been recorded. Sagitta serratodentata, QJI the other hand, failed at the colder stations of both ' Discovery ' and ' Challenger ' ; its minimum record f has now been reduced to 4 • 6° C'., the lowest temperature at which it had been taken previously being between 6 ' 6° and 12'2° C. at the Falkland Islands. Its definitive temperature limit in the Northern Hemisphere is at present 12 "2° C., but in view of the 'Discovery's' captures it may possibly prove to extend somewhat further north than its present record of lat. 60° 12' N. At any rate, it seems to be clear that it is not " bipolar," although subantarctic and north-temperate. The southern captures of hexaptera, serratodentata, and hamata, from all sources, have been plotted on the appended circumpolar chart, together with the mean annual surface isotherms of 12° and 6° C., as calculated by Dr. Schott. The former appears to indicate approximately the northerly limit of liamata as an epiplanktonic form, the latter similarly to indicate the southerly limit of serratodentata. The definitive temperature limits given in the ' Siboga ' Report already cited require amendment as follows : — hexaptera, lowest temperature, — 2° C. ; serratodentata, lowest temperature, 4'6°C. ; liamata, highest surface temperature, 12'7°C., lowest temperature, — 2° C'. f This record is, however, of a single specimen, and the species had failed at the two previous stations (compare p. 3 above). It is therefore, possible that we are dealing merely with an isolated specimen, which had drifted beyond its natural limits. CHART OF THE ANTARCTIC REGION, SHOWING THE RECORDED OCCURRENCES OF THE THREE TYPICAL SPECIES OF CH.ETOGXATHA ; AND THE APPROXIMATE NORTHERN LIMITS OF HAMATA AS A SURFACE FORM (ISOTHERM OF 12'0 C.), AND OF SERRATO-DENTATA (ISOTHERM OF 6° C.) ARE ALSO SHOWN. NEMATODA. VON DR. v. LINSTOW. (1 Plate.) LEPTOSOMATUM AUSTRALE. 2. DIESE Art i.st die griisste aller bekannten freilebenden Nematodcn ; das Weibcken crroicht cine Liinge von fast 50 mm. ; die Farbe der Spiritus-Exemplare ist gelblich- hraun. Der Korper ist lang gestreckt und scklank ; die Breite vcrliillt sick zur Lange wie I : 82-88 ; das Kopfencle ist stark verdiinnt, das Sdiwanzende nur wenig und in beiden Uescklecktern abgerundet. Die Cuticula ist sehr dick, 0 '015(5 mm. breit, und mehrschichtig, die iiussere Lage farbt sick sckwack dun-k Borax-Carmin, die iunere nickt ; eine Querringelung feklt ; am Kopfende triigt die Cuticula 14 Liingsreiken kurzcr, breiter Dornen oder Borsten, die tkeils senkreckt von ikr abstehen, tkeils gekriimmt und mit der Spitze nack vorn gericktet sind ; naek kinten werdeu sie immer sparsamer und versclnvinden etwa 1 ' 2 mm. vom Kopfende entfernt ganz, am Sckwanzende treten sie in aknlicker Weise wieder auf; sie steken einzeln oder zu zweien oder dreien neben einander. Das Kopfende ist gerade abgestutzt ; 0 ' 023 mm. vom Sekeitel entfernt stekt eiu Kranz von 10 Borsteu oder Stackeln, in den Seitenlinien je eine einfackc, in den Submedianlinien doppelte ; dicht dakinter bemerkt man jcderseits in den Seitenlinien ein Scitenorgan ; 0' 25-0 '28 mm. vom Sekeitel finden sick 2 dunkle Augentiecke. Von der Subcuticula erkebeii sick nack innen 4 Langswiilste, ein dorsaler, ein ventraler und z\vei lati-rale ; im Kopf- und Sckwanzende sind sie miicktig entwickelt, im langen, mittleren Kiirpertkeil aber \vird ikre Hiike sekr verringert ; ikre Miicktig- keit ist kicr nur l.]-2 mal so stark \vie die Dicke der Cuticula. Der Dorsalwulst ist am sckmalsteu, und wirtl in der Mitte des Korpers \vie der Ventralwulst zu einem sckmak-u, die jMuskulatur trennenden Kamin reducirt ; Dr. de Man* findet in seiner yurtrctrlicken Arbeit iiber die auf der Reise der " Belgica " gefundenen Nematoden bei den verwandten Arten Thoracostoma Minium v. Linst. gar keine Dorsal- und Ventralwiilste. Die Seitenwiilste sind stark entwickelt und nekmen jeder etwa TO~I> (^er Korperperipkerie ein ; sie besteken aus einem dorsalen, einem mittleren und einem ventralen Tkeil und sind iiberall mit Zellen durcksetzt, welcke grosse, tkeils blasse. tkeils sckwarz pigmeutirte Kerne und vielfack Kernkdrperchen * de Man, Resultats du voyage du S. Y. Belgica en 1897-1899. Zoologie, Nematodes libres, Anvers, 1904, pag. 26, tab. vii., fig. 8 j. 2 DR. V. LINRTOW. cntli.il ten. Der dorwde und ventrale Thcil sverden von gestreckten kolbenformigen Striiugen gebildct, wie sie im Quersehnitt erscheinen, auch die in ilmcn lu'genden Zellen sind langlich rund, wiihrend die Zellen des mittleren Theils meistens kugelrund sind. Der Ventralwulst ist starker als cler dorsale ; er wurzelt auf der Subcuticula mit schmaler Basis und verbreitet sich nach innen, alter nur im Kopfende ; im grossen mittleren Korpertheil ist er nur eine schmale Leiste ; ganz vorn, in der Niihe der Augenflecken, sind alle 4 Langswiilste geschwunden und die Muskulatur bildet einen zusammenhangenden Ring auf Querschnitten. In der Leibeshohle, zwischen den Muskeln und den Langswiilsten einerseits und dem Verdauungstract und den Geschlechtsorganen andererseits liegen zahlreiche freie Zellen, eiformig oder kugelrund, mit grossem, theils blassem, tlieils schvvarz pigmentirtem Kern, oft mit Kernkorperchen, welche den Zellen der Seitenwtilste durchaus gleichen ; besonders zahlreich und dicht gedrangfc finden sie sich vorn und hinten im Korper, im Kopf- und Schwanzeude, besonders grosse, die 0' 048 mm. lang und 0' 044 mm. breit sind, sieht man O1 30-0* 48 mm. von einander entfernt, binter einander liegen ; die durchschnittliche Grosse ist 0'02G mm. und die des Kerns 0'014 mm. Die 4 Langswiilste theilen die Langsmuskeln in ebenso viele Felder ; im Kopf- und Schwanzende ist die Muskulatur machtig entwickelt, bis 0'039 mm. dick, withrend sie im tibrigen Korper nur li-2 mal so dick ist wie die Cuticula ; am mannlic-hen Schwanzende steben parallele Aluskelziige, die schriig von vorn und der dorsalen nach hinten und der ventralen Seite ziehen. Im Kopfende sieht man 2 dunkle Augenflecke, die nicht in der Cuticula liegen, sondern der Aussenseite des Oesophagus eingepflanzt sind ; sie sind rothbraun und stehen 0 ' 1 5 mm. vom Scheitelpunkt entfernt ; sie finden sich aussen von den dorso- lateralen Schenkeln des dreischenkligen Oesophagus-Lumen uud bestehen aus je einer Linse, die innen von einem Pigmentbecher umfasst wird. Zur Perception von Bildern konnen diese unter der dicken Cuticula und der starken Muskulatur liegendeu Sehorgane wohl uicht dieneu, wohl aber, wie bei Epibdella, wo 4 Ocellen mitten im Oehirn liegen, zur Unterscheidung von Hell und Dunkel. Auch de Man * findet bei Thoracostoma selosum v. Linst. und Thoracostoma antarcticum v. Linst. die Augenflecke an der Aussenseite des Oesophagus, aber nicht dorsolateral, sondern, wie es scheint, lateral. Der Oesophagus nimmt beim Mannchen ^, beim Weibchen ^ der ganzen Thierliinge ein ; das Lumen ist di-eischenklig und der eine Schenkel ist, wie in der Regel, ventral gerichtet ; Langsmuskelziige, die radiiir gestellt sind, durchziehen das ganze Organ und dienen durch Erweiterung des Lumens zum Ansaugen von Nahrung ; 3 lange Driisen, 1 dorsal, 2 ventrolateral, durchziehen den Oesophagus der ganzen Lange nach; am Kopfende bilden sie erweiterte Ausmuudungsgange, die 0'12 mm. vom Scheitelpunkt in das Oesophaguslumen einmiinden. * Op. cit. pp. 31 u. 39, tab. x. fig. 9, f. FREE NEMATODES. 3 Der Darin besitzt eine dicke Tunica propria ; das Epithel wird vun breiten Zellen gebildet, die eine Langsstreifung zeigeu und einen bald blassen, bald schwarz pigmen- tirten Kern enthalten. Ein Nervenring umgiebt den Oesophagus 1*18 mm. voni Kopfende, etwa an der Grenze von dessen 1. und 2. Viertel : seine Dicke betragt Q'018 mm. und er enthalt ovale, 0'0156 mm. lange und 0'0104 mm. breite Ganglienzellen. Leimdriisen, welche bei anderen freilebenden Nematoden am Schwanzende miinden, felileu hier ganz, der Ratim hinter dem Anus ist von Zellen der Seitenwiilste erfiillt. Das Mannchen wird 37 '7 mm. lang und 0'4G mm. breit ; der Schwanz macht T, 'ri- der ganzen Lauge aus ; 0'2G mm. vor der Cloakenijft'nung in der Mittellinie miindet die Priianaldriise in einer rundlicheu Vorragung des Korpers, die eine becherartige Offnung triigt ; in diese miindet die kolbenformige, 0'16 mm. lange mid 0'034 mm. breite Driise ; die beiden Cirren siud sichelfb'rmig gekriimmt und in der Mitte verdickt, ihrc Lange betragt 0'22 mm.; dorsal von ihnen liegt ein 0' 18 mm. langer, stabfb'riniger, an beiden Enden abgerundeter Stiitzapparat ; die Hoden erfiillen die hinteren -* des Korpers ; Papillen fehleu ganz. Das Weibchen erreicht eine Lange von 49 '5 mm. und eine Breite von 0'56 mm. ; das Schwanzende uimmt 2--J-7,- der ganzen Lange ein ; auch liier sind die Geschlechts- organe weit nach hinten geriickt : die vordere Kb'rperhalfte beherbergt sie gar nicht ; thcilt man die Lange des Korpers in 10 gleiche Theile, so liegen Uterus und Ovarien im 6.-8. Zehntel ; die Vulva miindet etwa an der Grenze des 2. und 3. Drittels, sie theilt den Korper im Verhaltniss von 1 1 ; 6 ; die Eier liegen im Uterus in einer Reihe ; sie sind gross und wenig zahlreich ; die grossten, welche der Vulva zuuiichst liegeu, sind 0'7D mm. lang und 0'31 mm. breit. Es fragt sich, welche Function die Seitenwiilste und die freien Zellen haben kbnnteu ; zur Nahrungsaufnahme dienen sie oftenbar uicht, da die Cuticula zu dick ist und Oesophagus und Darm eine normale Ausbildung zeigen ; ein Absonderungsorgan kt'inncn sie auch nicht sein, da ein Ausmiindungsgang nach aussen felilt ; sie werden also eine Bedeutung fiir den inueren Stotfwechsel haben und halte ich es fiir wahr- scheinlich, dass sie die Function von Lymphdriiseu besitzen. Die parasitischen Nematoden habe ich friiher * eingetheilt in Secernentes, Resorbeutes und Pleuromyarii. Secernentes siud Xematodeu mit voll eutwickeltem Oesophagus und Darin, welche schmale und hohe Seitenwiilste besitzen, die eiu Langsgefass enthalten ; die Gefasse der beiden Seiten vereiuigen sich vorn in der Gegend des Oesophagus zu einem, das ventral im Porus excretorius ausmiindet ; die Seitenwiilste scheineu die Function von Niereu zu haben ; die Arten leben im Verdauungstract ihrer Wirtlie. Resorbentes wurden Nematodeu mit breiten und niedrigen Seitenwulsten geuaunt, denen ein Gefiiss und ein Porus i'clilt ; die Arteu leben nic im Verdauungstract der Wirthe, sonderu in oder an anderen innereu Organeri, oft fest von Bindegewebe * Arch. f. inikr. Anat. xlix. (1897), p. 620. VOL. III. Z 4 DE. Y. LINSTOW. umwachseu ; die Ernahruug erfolgt hier offeubar clurch Aufsaugung seiteus tier Seiten- wiilste durch die Cuticula hindurcb. Pleuromyarii habcu statt cler Seiteuwiilste Muskelu in der Seiteiiliuien. In dieses System passen die freilebeudeu Nematodeu niclit hiiieiu, fiir die ich Abtheilung der Adenophori aufstellen mochte. Dieselben besitzen schmale Seitenwiilste mit gekernten Zellen und ohne Langsgefiiss, welclie als Lymphdriiseu zu functioniren schemeii ; wenu -ein Porus excretorius vorhanden ist, so ist er die Ausraiindung einer Ventraldriise. ERKLARUNG DER ABBILDUNGEN. r, Cuticula ; a, Augenfleck ; /(, Nerv ; o, Oesophagus ; (/, IJarm ; m, Jluskeln ; dr, Dorsal- ; i-l. Ventral- ; /, Latcrahvulst oiler -Feld ; z, freie Zellen ; *, Seitenor^an ; j>, Pritanaklriise ; dm, Driisen- miindung ; r, Vagina ; u, Uterus ; h, Hoden. FIG. 1. — Mannchen, in. transversale Muskeln am Sehwanzende. Vergr. 5. „ i'. — Weibchen. Vergr. -f. „ o. — Kopfende. A^ergr. J-y". FIGS. 4-8. — Querscbnitte. Fief. 4. — Oesophagus mit der Einmiindung der Driisenausgange iu das Oesopliagus-Lumen. Vergr. J--J-. „ 5. — Oesophagus mit den Augenflecken. Vergr. J-f-. ,, (i. — Oesophagus-Gegend. Vergr. i^. ,, 7. — Mittlerer Korpertheil, Theil cler Korperwandung in der Seitenlinie. Vergr. —}-. „ 8. — Querschnitt des Weibchens hiuter clem Uterus. Vergr. J-"a. „ 'J. — Liingsschnitt vom Mannchen durch die Praanaldriise, parallel mit derselben verlanfeu transversale ]\luskelu. Vergr. J J'". „ in. — Cirrus und Stiitzapparat. Vergr. J-f-. Antarctic (Discovery) Exp Aut.del. ; CESTODA. By ARTHUR E. SHIPLKV, M.A., F.R.S., Fellow and Tutor of Christ's College, Cambridge, and l/niversity Lecturer in the Advanced ^Morphology of the Invertebrata. (1 Plate.) THE only Cestodes brought back by the naturalists of the 'Discovery' were three species, all of which were found living together in the stomach of Ross's Seal, Ommatophoca row. The three differed markedly in si/e, in the shape, number and relative pro- portions of the proglottides. so that there is no doubt that, we are dealing with three distinct species, and not with different stages in the growth of members of one species. All the specimens were pickled in Perenyi's fluid, and arrived in an excellent state of preservation. The largest of the three species is undoubtedly the same animal which Baird, in 1853, named Bothriocephalus antarcticus. I give below Baird's diagnosis, and then add a few remarks upon the anatomy of the specimens. DlBOTHRIOCEPHALUS ANTARCTICUS. Jj:>, p. 25, Aniiulosa. pi. sxxi.. h'g. 4 and 4a. " Head conical, elongated, smooth, with two lateral opposite fossettes. At the lower margin of each fossette there are two small rounded projecting lobes. Body rounded ; from the neck some way downwards it is quite round or cylindrical, and the articulations are very numerous and very small, appearing like mere ridges across. Lower down, the body becomes flatter and the joints larger and more developed ; lower margin thin. An impressed line runs along the centre of the body through its whole length. Length, about 9 inches; greatest breadth of body, about 3 lines." Baird's specimens measured about 9 inches, say about 23 cms. Most of the specimens at my disposal were just under 10 cms., but a couple, apparently young, barely measured 3 cms. The specimens were obviously immature, only in t lie- most posterior of the longer examples were uteri and ova to be found, and the latter in very small numbers; I am inclined to think also that these specimens had contracted when being killed, the anterior end of the body not being so munded as Baird describes. The greatest breadth is 7mm. in the largest specimen. 7. -2 ARTHTJE E. SHIPLEY. The body tapers anteriorly, and to a slight extent posteriorly. There is no true neck, the proglottides beginning immediately behind the head ; they are at first extremely short from before backward, a feature they retain, though to a lesser degree, even at the hinder end, where it takes some three to measure a millimetre. The posterior edge of each proglottis overlaps the succeeding one to a marked extent. The head is conical, 3 mm. in length and 3 mm. in breadth posteriorly ; anteriorly it lessens to a bluntly pointed apex. Dorsal and ventral lie the two suckers. These suckers are deep, with cleanly cut edges, for the most part curled in (fig. 7), and in all cases enwrapping some foreign substance, perhaps a portion of the mucous membrane of the host. The impressed line running along the whole body, referred to by Baird, is only on the ventral surface, and is due to the median opening of the reproductive organs and of the uterus. The nervous system consists of two very conspicuous nerve cords, which lie parallel with the longitudinal excretory canals, and about one quarter the distance of the latter from the edge of the proglottis outside the canal. The cords fuse together in the head. The longitudinal canals of the excretory system are also conspicuous, and are surrounded by thick walls ; they break up into an anastomosing tangle of ductules in the head. There are also small canals which lie close under the surface at the edges of the proglottides, usually two at each side (fig. 2), but they also break up from time to time into twisting branchlets. The overhanging edges of the proglottides, especially of the posterior ones, are very richly supplied with water- vascular tubules. It is possible that these may have a certain hydrostatic action, and serve to erect these free edges when fluid is directed into them. The confused meshwork of muscles in the head straighten themselves out iu the neck and fall into regular rows. Of these there are six or seven dorsally and six or seven ventrally (fig. 2), but at the sides the rows tend to merge and lose their distinctness. Each row is separated from the next by very clear and distinct connective tissue fibrils running parallel with one another. The muscles in these rows consist of bundles of various sizes containing from six or seven up to fifteen or twenty fibrils. Running between every two or three of these bundles are some slight and radially arranged connective tissue fibrils, which, with the concentric fibrils of the same nature, serve to divide up the tissues into a series of little squares. No muscle fibres penetrate the parenchyma within the central area, bounded at the sides by the nerve cords and dorso-ventrally by the innermost layer of muscles. The penis is conspicuous and very muscular, it opens in the anterior edge of the proglottis just where it joins the one in front, and is concealed by the overlapping end of the preceding proglottis. Close behind it opens the vagina, and behind this again the uterus, all in the middle ventral line. There is a large vesicula semiualis. The testes arc scattered throughout the parenchyma of the central part. The ovary is rather branching; it lies towards the posterior end of each proglottis, is deeply CESTOrtA. stained and fairly conspicuous. The yolk-glands are widely scattered through the peripheral parenchyma. The uterus is not fully developed in our specimens, which must lie rather immature. It consists of few branches somewhat rosette-shaped. The ova are thin-shelled, and measure 0'032 by 0'028 mm. DlBOTHRIOCEPHALUS SOOTTI. The second species of DibothriocepJialus found in the alimentary measured about 8cm. in length (fig. 3). One attained a length of 'Jem., but the other three or four specimens were shorter. The number of proglottides is some 150. The head is rounded, not at all conical, but like the amber mouthpiece of a Turkish pipe (fig. 4). The slit-like grooves are dorsal and ventral. The head measures 1mm. across, and perhaps a little less from before backward. It is succeeded by a neck which, in some specimens, is a little narrower than the head ; in others about as broad. The proglottides soon begin to be evident, but I do not think one can say there is no neck. In this respect this worm differs from />. h'tan* of Leptonyx woiinc/ius, AVagn., Plioc/i Imrlntfi, Mull., and P. annellctta, Nilss., which, in some respects, it resembles. The proglottides are at first some five times as broad as they are long, but sooner or later — and it depends upon the state of contraction of the worm when killed, how soon or how late — the proglottides become square, with parallel sides, and they remain square until the end. The posterior border is slightly thickened, and stands out at right angles from the body. It practically does not, however, overlap the succeeding proglottis. The reproductive organs consist of numerous testes lying scattered superficially through the proglottides ; the ducts of these presumably unite, though they could not be seen, and open into an exceeding muscular penis, which in most cases is protruded from the proglottis. The penis is situated in the middle line close to the anterior edge of the proglottis. It bears no hooks. Close behind it opens the vagina, which makes a coiling course backwards to where the two short oviducts from the ovary meet it. The ovaries are two, somewhat pear-shaped ; they lie each side, near the hinder end of the proglottis behind the uterus, and are of fair size. A minute shell gland is visible at the juncture of the oviducts. No tube entering the uterus is visible. The uterus is roomy, it opens on the ventral surface in the middle line, and about half-way along the proglottis. The opening is circular. Just within this opening the uterus forms a spherical chamber, which contains a fair number of ova. From this chamber two or three lateral branches diverge, and these may be cut twice in one plane, but in no sense is the uterus rosette-shaped. The ova measure on an average 0'04mm. by 0'03mm., but the shape varies; some 4 ARTHUR E. SHIPLEY. are rather more rounded than those of the other two species, and some have more pointed ends. The egg-shell is thick, with two clearly-defined contours. The yolk-glands are easily recognised by their lirown and glistening appearance. Like the testcs they are scattered, hut they lie more superficially 1han the latter. Although there is little differentiation between the medullary and the cortical regions, it is plain that the yolk-glands lie in the cortex and the testcs in the medulla. The epithelium of this Cestode consists of unusually large cells, somewhat columnar in shape, with their square outer ends pressed against the cuticle, and their inner ends tapering (fig. 7). Their nuclei lie about, but not quite at, the same level, near the inner end. The parenchyma is loose and stains but slightly, it is traversed by but few muscle fibres. The single pair of longitudinal excretory canals are conspicuous in sections, and so are the nerve trunks. There are numerous small excretory tubules running just below the external epithelium. I have ventured to dedicate this species to Captain Scott, the distinguished commander of the Antarctic Expedition, though 1 am well aware that there is a certain delicacy in doing so. Some people have a horror of Cestodes, and do not care to have their names associated with them. Dibothriocephalus scotti. — Length of specimens 9cm. and under ; number of pro- glottides about 140 ; head rounded, diameter 1mm. ; average width of middle proglottides about 2mm. ; very short neck. Posterior edges of proglottides stand out, but do not appreciably overlap the anterior end of succeeding proglottis ; uterus spacious, with a few diverticula, not a rosette ; ova 0'04 by O'Ooinm., with thick shell. DIBOTHRIOCEPHALUS WILSONI. This is a very attractive little tapeworm of few proglottides, which I have ventured to dedicate to my friend Mr. E. A. Wilson, M.B., who was both a doctor and a zoologist in the 'Discovery.' It somewhat resembles Krabbe's Dibothriocephalus Inncvnfiifux, from Phoca barbata, but is much smaller. The length varies from 4 to 5 '5mm. In the larger forms the greatest breadth is 1mm., this occurs in the region of the last segment but one, or perhaps two. The breadth of the head is a little less than 0'5mm., and its greatest length is about the same. The number of the proglottides varies from nine to thirteen or fourteen. There is no neck, the first proglottis lying close to the head. The proglottides gradually widen until they reach a breadth of 1mm., and in this region are somewhat crumpled (fig. 8). The last proglottis is shaped like a truncated cone, rather indented at the hinder narrower end. The hinder edges of the proglottis only slightly overlap the anterior edge of the following proglottis ; they are in all eases but the last wider than the CESTODA. 5 anterior border of the .same proglottis, and thus each proglottis has, like the last, the outline of a truncated cone. bur it i.s turned the other way up. In the centre of each of the middle proglottidea is a dark line caused l>y the opening of the penis, the oviduct, and the uterus. The penis is most anterior, and is very muscular, it is in many cases exserted. The liase of the penis passes into a spherical vesicula seminalis. The testes are scattered through the central tissue. The oviduct crosses the duct of the uterus, which is very short and practically hardly exists, and runs backward to the ovary and the shell-gland which lie behind the uterus. The uterus is but slightly convoluted and contains few ova, they measure 0'04'J by 0' 035mm. ; at any rate, that is about the average, for they vary a good deal in their dimensions. They have a single and not very thick egg-shell. Like the cells in />. wotti, the epithelial units of D. icilvoni are remarkably well defined and show but little differentiation. The parenchyma again is, at am rate anteriorly, not the vacuolated, spongy-looking tissue which one sees in the older proglottides, but consists of plump cells, well defined, full of protoplasm, with nuclei near the edge. Dibothriocephalus irilxoiii. — A small form, length 4 to 5 • 5mm. ; greatest breadth 1mm. ; nine to thirteen proglottides, like truncated cones ; the last is inverted ; no neck ; edges of central proglottides rather crumpled ; posterior edges but slightly overlapping. It is a remarkable fact that the only Cestoda brought back by the naturalists on the 'Discovery' were obtained from one (and that by no means a common one) animal, Ommatophoca roxxi, or Ross's Seal, an animal, in Captain Barrett-Hamilton's words, so little known that it " might, until a year or two ago, have claimed, and claimed justly," along with Weddell's Seal, " to be considered amongst the rarest and most obscurely known of all mammals.'1* It is also remarkable that the Cestoda should all belong to the same genus. If we want to have the history of the Dibotkriocephalid species which we find in this animal, the smallest of the Antarctic seals, we must look to its food. Ross's Seal is remarkable for the feebleness and variability of its dentition. " It seems probable that the exact number of its teeth is not of importance to this animal. "f Apparently it lives on soft food. Wilson mentions, in the work just ., and opening of vagina, o.v. „ 1. — Section through epidermis and external parenchyma of D. scotti. „ 8. — View of D. wilsoni, x 15. a^ 8 6. Antarctic (Discovery) Exp E Wilson .Cambridge 1 & 2 Dibothriocephalus ant,arcticus. 3-7 D scotti 8 D. wilsoni. CCELENTEEA. I.-ALCYONAEIA, By SYDNEY J. HICKSON, M.A., F.R.S., Professor of Zoology in the Victoria University of Manchester. (•2 Plates.) THE collection of Alcyonaria does not present many very remarkable features. The most interesting species is Ceratoisis spicata, which forms an important connecting link between the groups of species formerly separated into the two genera Ceratoisis and Primnoisis. It is quite unlike any species that has hitherto been discovered. Primnoella divergens is an important new discovery, as it exhibits many characters of the genus Caligorgia, and may be regarded as a connecting link between the two genera. Clavularia fi-nnkliniiimi and Alcyonium paessleri were found by the ' Southern Cross ' expedition off Franklin Island. It is a remarkable fact that not a single specimen of either of these genera was obtained by the Scottish National Antarctic Kxpedition. ThiKiiiir//. Localities 1. — W.Q., March 21, 1902, 30 yards from ship on Port Quarter. 8 fms. 2.— W.Q., March 21, 1902. 10 fathoms. 3. — W.Q., March 18, 1902. 10 fathoms. 4.— W.Q., June 15, 1902. 122 fathoms. There are many specimens of this species attached to stones, worm tubes and other foreign objects. I have little doubt they belong to the same species as those described 2 A VOL. III. 2 SYDNEY J. HICKSON. by Professor Koule from 10 fathoms off Franklin Island. At first it seemed possible that a new specific name should be introduced for these specimens, as they differ from the description of the type in size, in the character of the stolon, and in the absence of spicules in the tentacles ; but on further examination of the specimens from locality 4, and some small specimens from other localities that I had previously overlooked, I came to the conclusion that the species is very variable and that these specimens cannot be satisfactorily distinguished from C. frankliniana. The specimens are found attached to shells, stones, and worm tubes, and the colonies vary in size according to the nature of their support and the number and character of the other organisms associated with them. The specimen drawn on Plate II., fig. 20, was encrusting a black stone and was not interfered with in any way by other organisms, but another specimen from the same locality [4], growing on a worm tube, was associated with Alcyonium paessleri, Polyzoa, Sponges, and other organisms. The stolon consists of a number of bands ramifying and anastomosing over the surface of the support, each about 2-3 mm. in width, but in many places these bands unite to form a continuous membranous stolon. I have already (2) pointed out that in C. nustralicnsis both ribboned and membranous stolons occur, and it is quite clear that this character of the stolon is not one that can as a rule be safely used for specific distinctions. A study of a number of specimens suggests very forcibly that the membranous condition is produced by an amalgamation of bands when the circum- stances of the support permit. The fact that the type specimen is described by Professor Roule as having " stolons membraniformes " is not sufficient evidence to separate his specimens from these as a distinct species. The zooids vary immensely in size. It is .true that I have not found any so large as the largest of Professor Eoule's specimens, 25 mm. in length and 5 mm. in diameter, but I have measured specimens 20 mm. in length and 3 * 5 mm. in diameter. They are scattered at distances of 2-5 mm. on the stolon bands, but are crowded together on the membranous parts. The body wall of the zooids is opaque, but may have been far more transparent in the living specimens. It is marked externally by eight well- defined longitudinal grooves. The tentacles are short and only partially retracted as in the type specimen. The spicules of the stolon and the basal portion of the zooids are long spindles with numerous short tubercles. A remarkable feature of many of these spicules is that one end is often truncated (PI. II., fig. 21 ; and see also Professor Pioule's figures (9), PI. XLVIL, 3a and 3c). They vary in size up to a maximum of about 0'3f) mm. in length. The tentacles of some specimens I examined appeared to be devoid of spicules, and I cannot determine whether this is due to maceration in the preservative or to natural conditions. Other specimens, however, exhibit two rows of short spicules (0*15 mm. in length) on the outer side of the rachis of the tentacles. ALCYONARIA. ALCYONIUM PAESSLERI. (Plate II., figs. 22, 23.) Alfymiitnn. /wWrr/, M;iy, Hamb. Magcl. Samtn., Alcyon. (1899), p. 0. Localities:—!. Off Mt. Erebus, February 8, 1902. 100 fathoms. 2. W.g., June 5, 1902. D. net hole. 50 fathoms. 3. W.Q., June 15, 1902. D. net hole. 12| fathoms. 4. W.Q., April 1. 1903. No. 6 hole. 124 fathoms. 5. W.Q., February 13, 1904. D. net, Hut Point. In addition to the specimens from the localities mentioned above several small specimens were found in other bottles. It is evidently a common and widely distributed species ranging from shallow water to depths of over 100 fathoms. The largest specimen was from locality 5 (Plate II., fig. 22). The colony is 50 mm. in height and 30 mm. in greatest breadth. It rises from a base of attachment of irregular form with a maximum width of 15 mm. There are 13 blunt lobes, of which the largest is 15 mm. x 7 mm. The anthocodiae of this specimen were nearly all completely retracted. The spicules of the anthocodise (of a specimen from loc. 3) are long spindles 0'35 mm. in length (Plate II., fig. 23b), and the spicules of the ccenenchym of the same specimen, clubs or short spindles •OS-O'l mm. in length (fig. 23a), as well as ;i number of longer spindles of variable size attaining to the same length as those of the anthocodise. The two specimens from locality 3 are attached to a black stone, the specimens from localities 1 and 5 had their bases bent round the very slender stem of a dead Ceratoisis (Primnoisis). The colour of all the specimens is orange or pale orange, except the specimen from locality 4, which is white. The smaller specimens are not branched. The specimen from locality 4 consists of a single lobe 10 mm. in height by 6 mm. in diameter. I have compared the specimens with a specimen obtained by the ' Southern Cross' Expedition in 24 fathoms off Franklin Island (3). They cannot, I think, be separated from the specimens of the species described by Dr. May (8) from Smyth Sound. The species of the genus Alcyonium that have been described from Antarctic regions are ,1. sollasi, from the Straits of Magellan ('Challenger'), .1. haddoni, Messier Channel ('Challenger') and A.antarcticum, off Heard Island ('Challenger'), and from Kerguelcn (Studer). It is difficult to give any very precise characters to differentiate these three species from Alcyonium paessleri, but it is probable that A. antarcticum and .1. WA^/' are larger species, the largest specimen of A. paessleri being considerably smaller than the type specimens of the other two species. Alcyonium haddoni may be of the same size as A. paessleri, but some of the long spindles are '7 mm. in length, about twice the size of any that I found in the specimens at my disposal, and the species is also 2 A 2 SYDNEY J. HH'KSON. characterised by the presence of a certain number of four-rayed spicules of a type which does not occur in A. paessleri. On the whole then I am inclined to believe that A. pufxsleri is distinct from the other subantarctic species. FAMILY ISID^E. In the 'Challenger' report on the Alcyonaria, Professors Wright and Stucler (14) proposed a division of this family into three sub-families, Ceratoisidinse, Mopseinae and Isidinfe, based upon the shape of the spicules. The study of many specimens belonging to the family has convinced me that this sub-division is unnecessary and inconvenient. The many variations of spicule characters that are found in the species of a single genus render these structures unsatisfactory for the purpose of wide systematic differentiation. If we take a single species from each of two of the sub-families and compare them, the differences observed in the character and arrangement of the spicules may seem to be of a higher rank than the usual differences between genera ; while, on the other hand, the examination of a large number of species of the same two genera will reveal so many intermediate conditions as to render the separation of the genera, on spicule characters alone, impossible. This kind of difficulty is particularly well seen in the case of the genera Ceratoisis and Primnoisis, which were placed by Professors Wright and Studer in the sub-families Ceratoisidinse and Mopseinse respectively. In both these genera the branches arise from the calcareous internodes, a character which distinguishes them from the genera Acanella, LepicUsis and Isis belonging to the same family. The spicules in both genera are flattened and scale-like, but in the species attributed to Ceratoisis they are fusiform, whereas in those attributed to Primnoisis they are irregular flattened scales. In Ceratoisis, moreover, some of the spicules project as thorny processes from the calyx, whereas in Primnoisis they do not project. In the description of the Alcyonaria from the Cape of Good Hope (4) I described a new species under the name Ceratoisis ramosa, which has many characters resembling some of the species of the genus Primnoisis, but the species appeared to me to differ so markedly from Primnoisis in having the spicules on the tentacles arranged longitudinally instead of transversely that I concluded it must belong to the genus Ceratoisis. On re-examination of the specimens I have confirmed this observation, but may add to it the fact that many of these tentacular spicules project slightly from the surface. The examination of the Antarctic specimens brings additional evidence to show the inconvenience of separating the two genera. The specimen of Ceratoisis antarctica was found in the same locality as that of Ceratoisis spicata ; the former undoubtedly belongs to the group of species hitherto called by the generic name Primnoisis, as mine of the spicules project from the surface of the calyx; the latter, however, has very long spicules, many of which project as thorny spines. The projecting spicules of the calyx of Ceratoisis spicata, moreover, resemble those of C. grandiftora in having the base bifid (Cf. Plate II., fig. 18a, with Prof. Studer's (10) figure Taf. v., fig. 34b), but whereas those of C. grandiftora seem to be nearly smooth on the surface, those ALCYONARIA. 5 of C. ftfiiciitu are covered with little wart-like projections. The spicules of the coenenchym of C. K[>i<;) has shown that A'unUii divaricata of Studer must be transferred to the genus /'rim/m,//,/, and this species is " sparlich verzweigt " (Studer 10, p. 643), the branching habit of our new species is not quite exceptional. The branching is irregular and approximately in one plane, so that a large colony would probably be flabelliform. Some of the branches appear to divide dichotomously, but in general the smaller secondary branches arise alternately from the large main branches. The colony as a whole has some general resemblance in its mode of branching to a species of Caligorgia, figured by Gray (1, p. 37) under the name l'r'/). The specimen is not sufficiently well preserved to enable me to state definitely that the dorsal mesenteric filaments are present, but certain groups of darkly stained cells situated below the stomodaeum probably represent these structures. These siphonozooids do not possess a tentacle. It was at this point in my investigation that a fire broke out in my laboratory and entirely destroyed the specimen. I am, therefore, unable to give any further description of the distribution of these siphonozooids. There is no doubt that they occur all along the thin part of the stalk and on the upper end of the bulb. I believe they occur also on the lower part of the bulb, but I made no sections to confirm the external features. It is not possible to make any definite statement concerning the presence or absence of calcareous spicules in the bulb. There are no calcareous bodies in the upper part of the bulb, nor are there any in the autozooids or siphonozooids of the rosette. In the one small piece of the dermis of the lower part of the bull) I could tind none, but it is just possible that a further search might have revealed them. 14 SYDNEY J. HICKSON. There can be no doubt that this specimen belongs to the same species as those described by Kolliker (7) under the name Umbdlul,'iifn'i. These specimens were live in number, and found by the 'Challenger' at depths of 1975 fathoms and 1950 fathoms in the south polar seas; the stage of growth of the 'Discovery' specimen being probably an older one than specimen E of the ' Challenger ' series. But although we may be satisfied to give the specimen Kolliker 's name, the careful description by Dr. Jungerseu (6) of a series of specimens of the north polar and deep Atlantic species, U. encrinns, has impressed me with the belief that in time these two species (U. encrinus and U. carpcntcri) will be merged into one. There is no doubt that they are closely related, but as accident has prevented me from further testing this opinion I must leave the problem for others to consider. The striking similarities in structure between these north and south polar forms of Umbellula is, however, a matter of theoretical interest. LIST OF MEMOIRS QUOTED IN THE TEXT. 1. Gray, J. E. Catalogue of the Lithophytes in the British Museum, (1870). 2. Hickson, S. J. Trans. Zool. Soc. LoncL, XIII., (1894), p. 338. 3. Hickson, S. J. ' Southern Cross' Collections, 11)02, p. 293. 4. Hickson, S. J. Marine Investigations in S. Africa, the Alcyonaria, Pt. II., (1904), p. 224. 5. Hiles, I. Willey's Zoological Results, Pt. II., (1899), p. 19C. C. Jungersen, H. F. E. Pennatulida, Danish Ingolf Expedition, Vol. V., (1904). 7. Kolliker, A. Penuatulida, ' Challenger' Eeports, Vol. I., (1880). 7A. Kolliker, A. It-ones Histologies, 18G4-5. 8. May, W. Hamburger Magalhaensische Sammelreise, Alcyonarien, (1899), p. C. 9. Roule, L. ' Southern Cross' Collections, 1902, p. 290. 10. Studer, T. Monatsber. K. Akad. Wiss. Berlin, 1878, p. fif.2. 11. Thomson, J. A., and Ritchie, J. Trans. Roy. Soc. Edin., XLI., (190G), p. 851. 12. Valenciennes. Voyage sur la Venus, 1846 (fig. only). 13. Versluys, J. Siboga Expeditie, Mon. XIIlA., (100(3). 14. Wright, E. P., and Studer, Th. Alcyonaria, ' Challenger ' Reports, Vol. XXXI., (1889). DESCRIPTION OF THE PLATES. PLATE I. FKJ. 1. — UmMlula carpcntcri (reduced to \ size). An, Crown of Autozooids ; It., Peduncular bulb. „ 2. — U. carpenter/,. Proximal view of crown of autozooids. Natural size. Si., Petaloicl area of siphonozooids ; D., Dorsal pctaloid area terminating in a large siphonozooid ; F., Ventral petaloid area ; G., An autozooid that was injured, the tentacles missing. „ 3. — U. carpenter/. Distal view of the crown of autozooids. a, the ninth or " Haupt " zooid. „ 4. — U. carpenter!. Four siphonozooids of the petaloid areas, lent., the single long tentacle of each siphonozooid, X 40 diams. „ 5. — U. carpenter!.. Transverse section of one of the siphonozooids of a petaloid area, x 120. Si., Siphonoglyph ; d. ?«., Dorsal mesenteries. ,, (!. — U. carpenter!. Transverse section of a small siphonozooid of the peduncular bulb, X 120. „ 7.— U. carpenter!,. One of the tentacles of an autozooid, to show the arrangement of the pinna', X 2$. „ 8. — Primnoella dicergens. Two whorls as seen in a spirit specimen, showing the manner m which the scales project on the surface, X 10. ,, 9. — Priinniii'llii ilirrrgms. A spicule of the calyx, X -r>0. „ lo. -Primnoella divergens. A spicule of the cocnenchym, x £>o. ALCYONAUIA. 15 PLATE II. FiG. 11. — Ceruloisix ili'lii-ithiln. A few branches of a colony, X '1. „ 12 — Ceraioisis delicatula. a, Spindle-shaped spicule ; 6, triangular plate, x Ki(». „ 13. — Ceratoisis antarctica. A terminal branch, X 12. „ IK — Ceratnixia antarctica. a, Spindle-shaped spiculu ; ?>, plate, xl»". ,, 15. — Ceratoisis tnitinr/ira. View of corona and folded tentacles, to show the arrangement of the spicules, x ca. 50. „ 10.— Ceratoisis spieata. A branch, x 2. At n. the horny nodes may be seen. „ 17. — Ceratiilxi* xjiirata. Side view of a calyx, x ca. :!(». „ is. — CiTiitoisix apicata. Spicules. «, Forked spieule of a calyx; b and c, irregular spicules of the cccnenchym and calyx base, x -r><>. .. 10.— 7% 10 Antarctic (Discovery) Exp Alcyonaria pi. I. .on, Cambridge Antarctic (Discovery) Exp. Alcyonaria pi .11. E Wilson, Cambridge. II.-HYDBOID ZOOPHYTES. BY SYDNEY J. HICKSON, M.A., F.R.S., Professor <>/ Z<><>/<>1.}. There is always a short conical hypostome armed with nematocysts, and occasionally this is surrounded by a circle of four rudimentary tentacles (fig. G, bl. f.). The body of the blastostyle is usually considerably dilated and has a superficial resemblance to a simple ovoid sporosac. Gronosome. — The medusoid structure of the gonosome is completely reduced in the male, but as no female blastostyles were found we can make no statement to the effect that the same is true of both sexes. The sperm cells (fig. 33, */>.) are found in a dense cluster between the ectoderm and endoderm even in the youngest blastostyles we have examined (0 • 1 mm. in length), and neither in these nor in the older blastostyles can we find any true medusoid structures. FAMILY PODOCORYNIDAE. In this family we include P»r<>rt/ne (Sars), Hydractinia (Allman), and other less well-known allied genera. The very interesting new genus IIydrodendrini,i (Xuttiiig) may, we consider, be now included in this family, as the species Hydr/'.) are all probably female and in the form of sporosacs. They occur in a single circlet round the base of the blastostyle. The upright branching stem of this specimen rises to a height of about 40 mm., ,-iuil is about 0'8 mm. in diameter at the base (fig. 9,/r. rite.). The ramification is irregular, the eight or nine terminal branches ending in some cases in a long filamentous process. The surface of these branches is remarkably smooth. The IIYDROII) ZOOPHYTES. 11 gastrozooids and blastostyles at the base of the stem are very similar to those of the basal encrusting part of the colony, but distally the gastrozooids arc .smaller and apparently less contractile, and blastostyles are absent. Specimen B. — Assuming that the pieces in the bottle containing this specimen all belong to one colony, we have estimated that the height .of the colony must have been at least 150 mm. There is no encrusting basal support as in specimen A, and the axes of the branches do not show any foreign hydroid or other kind of core. The branches arise irregularly and anastomose freely (fig. 10). They are circular in section, remarkably smooth on the surface, and their maximum diameter is about 3 mm. They are therefore much longer and thicker than the upright branching stem of specimen A, and we may add presumably older. Although there is no true basal part similar to that of specimen A, the encrusting habit is seen in places where sponge spicules and other foreign bodies have been overgrown by the colony. The skeleton is composed of a series of parallel intercommunicating chitiuous tubes, the superficial tubes being externally incomplete, but there are no definite ridges or spines on the surface as in the basal part of specimen A. On the larger branches there appear to be no zooids at all. At the distal ends there are numerous small immature zooids which may become either gastrozooids or blastostyles, as well as a considerable number of gastrozooids. These gastrozooids (fig. 8, (/z.) are about 1'5 mm. in height, and therefore slightly smaller than the majority of the gastrozooids of the basal part of specimen A. The mouth is on a conical hypostome which is surrounded by a series of filiform tentacles, 6-10 in number, and each one about 0 • 6 mm. in length. Proxirnally to the region where the immature zooids and gastrozooids occur there is a region with numerous ripe blastostyles (fig. 8, !>!.), and only a few gastrozooids. These blastostyles vary from 0'3 to 0'7 mm. in height, but the majority are larger than those of A. They have 4-8 tentacles 0' 1- 0 ' 2 mm. in length, and have in some cases a minute mouth. The blastostyles each bear from 1-5 sporosacs (fig. 7, ///'/'.) which in our specimens were all male, and when ripe about 0 ' 3 mm. in diameter. The sporosacs are borne just above the base of the blastostyle. The branch shown in fig. 7 is somewhat intermediate in character between the region of gastrozooids alone and the typical region of blastostyles. In comparing the two specimens we notice certain differences between the basal part of specimen A and specimen B which might be regarded by some authors to be of sufficient importance to necessitate their separation into distinct species. Thus, the surface of B is smooth, of the basal part of A ridged ; the gastrozooids arc smaller in B than in A ; the blastostyles of B are on an average larger than in A, and have a larger number of longer tentacles ; the sporosacs of B are larger and less numerous than those of A, and are situated above the base, and not at the base, as in A. More- over iu B the skeleton has the form of a series of parallel but communicating tubes, whereas in A it has the same irregular lacuuar arrangement that is found in //. «-/tinn/ii and other species. 12 SYDNEY J. HICKSON AND F. H. GRAVELY. The fortunate preservation of a small and probably young branching stem of specimen A, with gastrozooids at its proximal end similar to those of the basal parts and at its distal end similar to those of specimen B ; with a smooth surface similar to that of specimen B, and ramifying and growing without any axial support as specimen B does, may be regarded as conclusive evidence that the specimens belong to the same species. The species resembles Hydractinia in having sessile hydranths, a thick membranous hydrorhiza covered with a continuous sheath of ectoderm and provided with a lacuuar chitinous skeleton, and in having adelocodonic gonophores. On the other hand, it differs from many of the species of Hydractinia in forming large unsupported rhizocauline branching stems, and in the absence of dactylozooids. A species that has close affinities with //. dendritica is //. angusta, from 71° S. and 87° W. 400 metres (Hartlaub 9: pp. 7-8 ; PI. IV., figs. 1-6). It forms branching (?) cylindrical rhizocauline stems. It has also tentaculate blastostyles and no dactylo- zooids. But it has thorny processes on the surface, which in our species are confined to the basal part ; the gastrozooids of our species are quite twice as large and the tentacles are more numerous than in Hydmctinia angusta. It differs from Ilydrodendrium gorgonoides (Nutting 20: pp. 936-938; PI. I., figs. 1-6 ; PI. VII., figs. 1-2) from Hawaii, in having definite blastostyles, in the presence of a large hypostome on the gastrozooid, in the colonies being unisexual, and in other characters. It resembles Hydrodendrium in the occurrence of branching brittle rhizocauline stems, in the absence of spines on the surface, and in the absence of dactylozooids. Hydractinia angusta and Hydractinia dendritica form two interesting links in a chain connecting the ordinary species of Hydractinia with Hydrodendrium. It may be noted here that in addition to the species of IJi/ilnii-tiniti mentioned above that have no dactylozooids, Ilydractinia parvispina (Hartlaub), //. carnen, var. inermis, H. humilis, and H.pnivuti (Koss.) are said to have no dactylozooids ; and in other species described by Bonnevie (6), Hincks (11), and Allman (2) no mention is made of these peculiar zooids. The presence of dactylozooids cannot therefore be regarded as a character of the genus. FAMILY TUBULAMIDAE. GENUS TUBULARIA (Linn, emend. Allman). We have found in the collection what appear to lie three distinct species of Tubularia, but of these, one is represented by a single hydrauth, and one by two hydranths. The third species agrees fairly well with the description given in Bale's Australian Zoophytes of a species described in MS. by Halley from llobson's Bay. HYDIIOIT) ZOOPHYTKS. 13 TUBULARIA RALPHI. (Plate II., fig. 12.) T Maria ralphii, W. M. Bale, Cat. Austr. Hydroid Zoophytes Austr. Mus. (1S84), p. -\->. Localities.— W.Q., February 28th, 1902; -20 fins. Hut Point, October 18th and November 13th, 1902. Flagon Point, January 17th, 1902 ; 10-20 fms. This species is represented in the collection by a group of dead perisarcal tubes and a single hydranth which is not well preserved, as well as by a few immature specimens. Ili/dmsuiue. — The height of the colony is from 00-120 mm. In the W.Q. specimen, five long and slender hydrocauli arise from a contorted hydrorhizal plexus. Each hydrocaulus is unbranched, and considerably narrower at the base than at the distal extremity, where its diameter is about 0'8 mm. The perisarc covering the hydrocaulus is smooth and conspicuous, but becomes, very thin and transparent at the base of the hydranth. The hydrauth is flask-shaped, and has a dense tuft of distal tentacles and a circlet of about twenty or more proximal tentacles each about f) mm. in length. (toiiosomc. — The blastostyles arise immediately above the proximal row of tentacles. Owing to the condition of the specimen, their number could not lie accurately determined. The ripe gonophores (females only were observed) are somewhat pear-shaped, and provided distally with four rudimentary tentacles. The walls of the umbrella are very thin, but the sub-umbrella cavity is large, and usually contains more than one, but not more than three actinulse. No trace of tentacles could be observed on these larvse. The blastostyles are very short, and the gouophores are borne upon them in dense clusters, so that it is probable that in life they were not pendulous. The blastostyles arc about 2 mm. in length, and each ripe female gonophore about 1 mm. in length. The male gonophores of another specimen were not mature. The only printed description (4 : p. 42) of the type of this species which was found in shallow water in Hobson's Bay, Victoria, is so short that it is impossible to be certain that our identification of these Antarctic Tubularias is correct, but, except in the fact that our specimens are rather larger than the type in several measurements, there is no good reason for separating them from it. TUBULARIA HODGSONI. (Plate II., fig. 13, and Plate IV., fig. 34.) L«oiliti/.—\\.(l., January 1st, 1902; No. G hole; 130 fms. No. 11 hole, April 25th, 1903. Unfortunately, only two zooids of this remarkably interesting species were found. c 14 SYDNEY J. HICKSOX AND F. H. GRAVELY. Hi/drosome. — The hydrocaulus springs from a hydrorhiza composed of thin branches ramifying in a sponge. The hydrocaulus is uubranched, and rises to a height of about 40 mm. It is of almost uniform diameter throughout. The perisarc is thin, membranous, and ends rather abruptly a little below the hydrauth, which is marked off from the hydrocaulus by a slight constriction. The height of the cylindrical hydranth is about 5 mm. There is a dense tuft of about 60 tentacles round the mouth. The proximal circlet is composed of about 25 tentacles, 7 mm. in length. Gonosome. — There are about nine bunches of closely packed spherical gonophores attached in the usual manner to the inner or distal side of the proximal circlet of tentacles. From the position they occupy in the spirit specimen lying close alongside the wall of the hydrauth, it seems probable that in life the hydranth was pendulous. The blastostyles are about 5 mm. in length and the gonophores are 0 • 9 mm. in :liameter. The structure of the gonophores is extremely interesting. The umbrella wall consists (fig. 34) of an outer layer of simple ectoderm, a thin layer of mesogloea, and an inner layer of ectoderm cells, which appear to be tri-radiate in section, one of the radii projecting into the mass of sperm cells, and the other two radii forming a continuous thin membrane lining the sub-umbrella cavity. At the distal extremity of the gonophore the inner and outer ectoderm layers are continuous, and between them the umbrella wall is thickened and contains a ring of endoderm cells. In some cases there are four short tentacular thickenings of the ectoderm at the mouth of the gouophore (fig. 34). In the centre of the gonophore there is a well-marked manubrium or spadix, with a lumen and without any clearly-defined ectoderm covering. The sperm cells entirely fill the space between this endodermal spadix and the umbrella wall. The sperm cells lying in contact with the manubrium are evidently in the earlier stages of spermagenesis, those lying at the periphery of the sub-umbrella cavity in the later stages of spermagenesis (fig. 34, sp.), so that it may be said that the sperm cells ripen from within outwards. The absence of any well-defined canals in the gonophore, and the presence of four conical rudimentary tentacles, suggests affinities with Agassiz's sub- genus Thamnocnidia (1 : see 2, pp. 399-400, 406, and 41G), but apart from this it is not possible to find any close affinities with other species of the genus. TUBULARIA LONGSTAFFI. (Plate II., fig. 11.) Locality.— No. 6 hole, April 8th, 1903; 124 fins. Only a single specimen of this magnificent Tubulariau zoophyte was found, and it bears unfortunately only a single hydranth. As it appears to be quite distinct from Tubularia hodgsoni and does not agree with any other species of the genus that has hitherto been described, we propose to call it Tubularia IIYDIIOII) ZOOPHYTES. 15 Hyxt»n<'. — The hydrocaulus is unbranched and about 2 mm. in diameter at the distal end. It rises to a height of 70 mm. At its base, where it is extraordinarily slender, there arc three or four hydrorhizal branches. It is invested by a continuous smooth tube of perisarc. At the base of the flask-shaped hydrant li the hydrocaulus is slightly constricted. Just above this constriction the hydranth expands to form the support of the proximal circlet of tentacles. The tentacles of. this proximal circlet are 25 in number and about 12 mm. in length. Just above this circlet of tentacles arise the eight long slender blastostyles. From the base of the blastostyles the hydranth narrows rapidly to form the conical hypostome surrounded by a dense tuft of distal tentacles, each about 2 mm. in length. Gonosome. — The eight blastostyles are in the contracted condition of ppirit specimens about 14 mm. in length and bear a great number of flattened gonophores. The gonophores are all female, and about 2 mm. x 2'5 mm. in size. They have no radial or ring canals, but, like Tubularia hodgsoni, they have four rudimentary tentacles. Actinulge with proximal tentacles. This form appears to be most closely allied to T. spectabilis (Agassiz) from the coast of Massachusetts, described by Allman (2: pp. 414-5, see also pp. 416-7), in size and general form ; but as the description is not very full, it is not possible to determine the identity of the two species with certainty. It differs, however, from the description of T. apectabiUs in having the blastostyles disposed in a single row, and not in two or three rows one over the other. Moreover, the hydrorhiza of our specimens shows no sign of being " very much contorted, irregularly branched, and densely intertwined." CORYNIDAE. Species A. 1,,',-,1/lf,/.— W.Q., McMurdo Bay, February 20th, 1902; -20 fms. A single hydranth was found at the bottom of the bottle containing various hydroids from this locality, which appears to belong to some genus of the family <',n-//ii/i/iii: Without further evidence than we possess at present we cannot even venture to suggest the name of the genus to which it belongs. The hydranth is about 0'7 mm. in height, and almost spherical in shape. It has a conical hypostome and six scattered capitate tentacles. The presence of a short stolon or stem at the base of the hydranth suggests that the species is colonial in habit. No gonophores are present, 16 SYDNEY J. H1CKSON AND F. H. GRAVELY. Specie* B. (Plate III., fig. 17.) Localities.— W.Q., Hut Point, November 13th, 1902. W.Q., Hut Point, September 27th, 1902. East end of the Barrier, January 29th, 1902; 100 fins. Three specimens of a solitary (?) coryuiform hydranth were found in the bottles containing hydroids from these localities attached to the sponge spicule debris. The hydrocaulus is 3 • 5 mm. in length. The hydranth is 2 mm. in height and 0'6 mm. in diameter, cylindrical in shape, with short scattered capitate tentacles 0 • 3 mm. in length. The proximal end of the hydrocaulus is covered by a chitinous perisarc and gives off 3 or 4 hydrorhizal filaments (fig. 17, hrh. /.), for attachment to the sponge spicule debris. No gonophores are present. Bonnevie describes a solitary form, Coryne gigantea, from Hammerfest (7 : p. 15), but this species differs from our specimens in having a hydrauth longer than the hydrocaulus and in having the tentacles arranged in groups of three or four instead of singly. There is some reason for believing, from the evidence afforded by these specimens, that at least two species of Corynidae occur in the Antarctic Sea. This is an interesting conclusion, as no specimens of the family were obtained by the ' Belgica ' or ' Challenger ' expeditious, nor has the family been discovered yet in the Falkland Islands. Hartlaub (10 : pp. 505-509), however, describes two species of Coryne, one species of Syncorym and one species of Gemma ria from the coasts of Chili, etc. It is also noteworthy that these few specimens are the only Hydrozoa in the collection with capitate tentacles ; it is therefore quite certain that they are not detached zooids from other large colonies that we have found in the collection, and improbable that they represent initial stages in the life history of these large colonial forms. ^1 FAMILY CORYMORPHIDAE. The genera belonging to this family that are sufficiently well known to be generally recognised are Branchioceriantkus, Monocaulus, Corymorpha, Lampra, Gfymnogonos, Seterostephanus. The genus Branchioceriant/tus (Mark 15 and 16) appears to be perfectly distinct, and does not offer any difficulties to the systematist. Corymorpha (M. Sars, 1835) and Ileterostepliauus (Allman) differ from the other genera in producing in both sexes free medusiform gonophores. Allman (2 : pp. 395-6) introduced the genus Monocaulus for the species with adelocodonic gonophores described by Sars as Corymorpha glaciati*, and he included in the same genus Corymorpha pendula (Agassiz) and the giant deep-sea species Monocaulus imperator. IIYDROin ZOOPHYTES. 17 Bonnevie (5 : pp. 4G9-47l)in 1898 instituted the genera Lr/iiiiii'i/i>in>.f. This authoress includes all tlie species belonging to this group of genera with " medusoid " gonoplmres in the genus Corymorpha. All species with " pseudo- medusoid" gonophorea are placed in the genus Lampra, and those with " styloid " gonophores in the genus Gymnogonos. This classification appears to us to be reasonable and will probably serve a useful purpose for some years. Difficulties are sure to arise later when species are found with intermediate characters, but at present we can recognise three distinct steps in the degeneration of the medusiform gonophore which may be used for purposes of classification. There is the "medusoid" gonophore showing some evidence of degeneration, but retaining the endocodon or sub-umbrella cavity, the " pseudo- medusoid " gonophore retaining the umbrella wall, but with no sub-umbrella cavity ; and, lastly, the "styloid" gonophore with little or no definite trace of medusoid structure. LAMPRA PARVULA. (Plate III., figs. 15, 1G ; and Plate IV., fig. 35.) Localttit'*. — Off Hut Point and Flagon Point in McMurdo Bay. Sexually mature and full-grown specimens obtained from September to December, 1902, and September, 1903. Young specimens obtained January, February, March and October, 1902, and January, 1903. Depth, 10-20 fins. A great many specimens of this interesting little species were found in several tubes and bottles from the localities named above. They are attached by root-like processes from the basal end to polyzoa (fig. 15) and to a curious felt-work mass of substance that is mainly composed of sponge spicules (fig. 1C). Although Lniii/>ni jnirvula presents us with the largest hydroid zooid, except those of L. niiirnr/ihn and of Tubularia in the collection, yet they are considerably smaller than the zooids of any known species of Lmn^i'ii or Corymorpha. The zooids of the only known species of Gymnogonos, however, are only 10-20 mm. in height. Like many other species of Corymorphidae, the colour of the spirit specimens is dark reddish-brown. In habit the species closely resembles Lamprn fmciii (Swenander, 23 : pp. G-8, figs. 1-2) from the Trondhjem fjord, several specimens being usually found in groups more or less imbedded in the sponge debris mass. A few very young specimens were found attached singly to the stems of calcareous polyzoa (fig. 15), or more rarely to other hydroids. L. socin was found attached to the branches of Lnj>//<>/n //'.); at the proximal end it gives off a very large number of extremely delicate processes for attachment (fig. 14, hrh. /.). The hydranth is not separated from the hydrocaulus by a constriction. The proximal tentacles are 40-50 in number and about 40 mm. in length ; the distal tentacles appear to be about 7 mm. in length, but are matted together and cannot be clearly seen in the preserved specimens. t'. — Blastostyles branched ; 5 (?) mm. in length. FAMILY MYRIOTHELIDAE. (MVIUOTHELA?) (Plate III., fig. 18.) Locfiliti/:—\\.C}., Hut Point, November 13th, 1902. A single specimen of a hydroid belonging probably to this family was preserved in a separate tube from this locality. HYDROID ZOOPHYTES. 19 Hydi'osumc. — A solitary zooid. The hydrocaulus is about 8 mm. in height and about 2 mm. in diameter for the greater part of its length. At the base it is much thinner and gives off numerous hydrorhizal filaments (fig. 18, hrh. f.) for attachment to the sponge spicule debris. It is covered throughout its length by a thin chitiuous perisarc with transverse striatious. The hydranth is naked, about 6 mm. in length, and spindle-shaped, thickening gradually from the hydrocaulus, and then gradually tapering to form the conical hypostome. The distal half of the hydranth bears numerous short, thick, scattered conical or hemispherical tentacles (fig. 18, t.) the largest of which are situated just above the thickest part of the hydranth. Goiwsomi'. — No gonophores are present. Although we are unable to give a generic or specific name to this specimen, we are anxious to record the existence of a member of this family in the Antarctic Sea. Ilartlaub, in his summary of the Southern Hydroids, does not mention the family .at all, but Jaderholm (13 : p. 2.) records the occurrence of M. austro-georgiae from South Georgia. FAMILY SERTULARIIDAE. SKRTULARELLA SPIRALIS. (Plate III., figs. 19, 20.) L,',;illti/.—\\.Q., No. 10 hole, July 3rd, 1903 ; 130 fms. Several fine colonies of this species were obtained from this hole at the date fiveii above. It is perhaps noteworthy that no other specimens were obtained from any other localities, although at this particular spot the species seems to have been so abundant. Unfortunately, all the colonies were torn away from their attachments, so that in some particulars our description must be imperfect. JfydrnxoDH'. — The slender monosiphouic hydrocaulus is 250 mm. or more in height. It is bent alternately right and left at intervals of 5 mm., and at each geniculation two branches are given off from the major angle. Each of these brandies is about 40 mm. in length, slightly geniculated and piunately branched, the pinnules arising as before from the neighbourhood of the angles. Their internodes are about 2' 5 mm. in length. In some cases one or both of the branches themselves are elongated to form an axis similar to the main axis and give rise to secondary branches similar to the primary branches. The general effect of this method of ramification is to give the appearance of a spiral form similar to that so characteristic of the genus HydraUmania. The pinnules vary in length up to 30 mm. and are divided into a series of internodes by geniculatious, but these interuodes are not all of the same length (O'G-1'0 mm.), increasing somewhat in length in the distal parts. Proximally the nodes are not very clearly marked. 2 E -J 20 SYDNEY J. HICKSON AND F. H. GRAVELY. Each Intel-node of a pinnule bears one hyclrotheca at its distal extremity, but each iuternode of a branch bears three hydrothecas, one at the distal extremity, and the other two at intervals of one-third and two-thirds from the proximal end. The hydrothecse of the pinnules (fig. 19) are about 0'5 mm. in depth, 0'22 mm. in their greatest diameter, and 0'17 mm, in diameter at the mouth, and have three opercular flaps (fig. 19, op.) 0'09 mm. in length. They are somewhat shorter than this in the proximal regions of the pinnules. The two proximal hydrothecse of the internodes of the branches are decidedly shortened as regards that part of their length which is not adnate. The distal hydrotheca of each iuternode of the branches is nearly straight and barrel-shaped. A single straight hydrotheca, which is not adnate to any part of a hydrocaulus, is situated between the bases of each pair of branches (fig. 20, hth.). Apart from these, the main axis bears no hydrotheca}. A remarkable feature of the hydrauths is the presence of a loose sheath of ectoderm (fig. 19, ccf.) enveloping the base. The hypostome is conical and surrounded by about fifteen tentacles. Gonosume. — Only female gonothecte (fig. 19, f/t/i.) have been observed. They are 1 • 0 X 0'5 mm. in size, ovate, smooth, sessile, and attached below the bases of the hydrotheca) of the pinnules. The gonothecse are all empty, none of the gonophores being preserved. The planulse are developed in spherical or somewhat pear-shaped acrocysts (fig. 19, ac.), 0'4 mm. in diameter. This species seems to be quite distinct from any that has yet been described. SERTULARELLA PLECTILIS. (Plate III., fig. 21.) LucitlitiL's.—'W.Q., No. 6 hole, February 15th, 1902 ; 130 fms. W.Q., McMurdo Bay, February 20th, 1902; 20 fms. Several large, detached, tangled masses of this hydroid were found in the first- named locality ; but in the second locality only a single small colony 12 mm. in height attached to the stem of Campanularia verticillata was obtained. Hydrosome, — The hydrocauli are all extremely slender, not exceeding 0'12 mm. in diameter, irregularly branched, and — as they reached us — in an inextricable tangle. The internodes are about 0'6 mm. in length. The branches arise immediately below the hydrothecse (fig. 21). A single hydrotheca is situated at the distal end of each internode. As many of them are reduplicated (fig. 21, ;•. /it/i.), they vary considerably in length. The original length of each hydrotheca appears to be 0'4 mm., but one showing four reduplications is O'G mm. The greatest diameter is 0'15 mm., and at the mouth 0'13 mm. The wall is adnate to the hydrocaulus for about one-third of its original length. It is extremely thin. The margin has three opercular flaps, O'OG mm. in length. About fifteen tentacles surround the bluntly conical hypostome of the hydrauths. H YD IK HI.) ZOOPHYTES. 21 Giiin, Allman ; 3 : pp. 7G-77 ; PL 36, figs. 2, 2.) which bear uematophores only. The supporting tubes do not surround the hydrocladia-beariug tube, but leave it exposed on one side. The hydrocladia-bearing tube is divided into a series of internodes 1 mm. in length, and it becomes free from its supporting tubes at the distal end, so that the hydrocaulus then becomes monosiphonic. In Phunularia profunda (Nutting, 18: pp. GG-67; PI. VIIL, figs. 2-3), to which our species has some affinities, the supporting tubes entirely surround, the hydrocladia-bearing tubes, and the iuteruodes are of two kinds, longer ones supporting two hydrocladia and shorter ones bearing only one hydrocladium. Moreover, in Plumularia profunda the hydrocladia are supported on processes arising from the proximal end and not from the middle of the iuternodes as they are in our species. A short hydrotheca (0'2-0'3 mm. in height), adnate to the hydrocaulus but not aduate to the hydrocladium, is found at the base of each hydrocladium (fig. 23). The other hydrothecse are cup-shaped, 0'3 mm. in length and 0'2 mm. in diameter at the mouth. One, or sometimes two, arise from each iuternode of the hydrocladia, and each one is guarded by two nematophores above (i.e. distally) and a single one below. The margins of the hydrothecse are entire. Although the label of the bottle containing these specimens bears the inscription "has been dry," some of the hydranths are sufficiently well preserved to enable us to make out some features of the structure of the soft parts. The rounded hypostome is surrounded by a single circlet of about fifteen tentacles, each about 0'15 mm. in length. Gonosome. — The female gonothecse are 1 • 0 X 0 • 5 mm. in size, and have a remarkable shape (fig. 23, ? .) are narrow and bluntly ovate. They are not found on the same colonies as the female gonotheete. They are I'O x 0'4 mm. in size. Each of the female gouothecre contains one ovum. In ./"*. profunda, however, the gonothecse contain "a number of developing ova" (Nutting, 18: p. 07; PI. VIII., fig. 3). FAMILY CAMPANULARIIDAE. The character which distinguishes the hydrosomc stage of the Campanulariidae from the Sertulariidae and Plnmuli'intte no clear distinction can be drawn between the base of the theca and the stalk of the theca, theca and stalk forming a continuous tube, but there are other reasons for associating this sub-family with the Campanulariidae. The separation of Oln'liC>~>. Localltl^.—'W.Q., February 28th, 1902. McMurdo Bay ; - 20 fins. W.Q., February 23rd, 1902. Flagon Point. Several colonies of this very beautiful hydroid were found creeping on the stems of Halecium arboreum. The zooids are, with the exception of those of its supporting species, the largest among the Calyptoblasts of the Expedition, and the large bell-shaped hydrothecse with toothed margins — mounted on their straight but graceful pedicels- are very striking. Hydrosome. — The creeping hydrorhiza gives rise at intervals to a number of straight, upright, tinbranchcd hydrocauli from 5 to 10 nun. in height. Each hydrocaulus has two or three very obscure annulations at the base, and one clearly marked convex ammlation immediately below the hydrotheca. The hydrothccoi are bell-shaped, slightly curved at the base, and then straight, expanding gradually throughout their whole length. They are from '2 ' 5-3 • 0 mm. in VOL. in. ^ y 20 SYDNEY J. HICKSOX AND F. II. GRAVELY. length, and from 1 '5-2*0 mm. in diameter at the mouth. The margin is armed with 15-20 blunt deuticulatious. The hydranths are large, but of the usual form in the genus, and provided with about 30 tentacles 1 * 5 mm. in length. Gvnnxoiiic. — The mature gonotheca is 2'5 x 1'2 mm. in size, tall aud cylindrical. The proximal part of the gonotheca is slightly swollen, and the distal end almost straight. It is supported by a short aunulated pedicel arising directly from the hydrorhiza. The specimens attributed to Hartlaub's species differ from the type in one or two particulars. The hydrothecse are not so fully expanded distally, the reduplications (?) of the stem are not so well-marked, and the gonotheca! are very different in shape from those of the specimens from Calbuco.* But without further evidence as to the sex and structure of the gonophores of this type we do not feel justified in creating a special specific name for them. SUB-FAMILY HALECIINAE. The genera that are usually included in the sub-family ILdecitnae (Haleciidae, Hiucks) are characterised by the rudimentary condition of the hydrothecse. The tubular structures arising from the hydrocladia surround, like a collar, the base of the hydranths, but are quite insufficient to enclose and thereby afford protection to them when retracted. It is, in our opinion, unfortunate that the term " hydrophore " has come into general use for this rudimentary form of hydrotheca. There are many examples to be found in the CulyptMixtca of hydrothecse that are not cup-shaped, such as the cylindrical hydrothecae of Sci'tularclla formica and Syntheciwn cylirtdricum (see Nutting, 19.: p. 14), and it would be practically impossible to limit the use of the term to hydrothecse that are tubular or cylindrical in shape. The use of the term hydro- phore for those hydrothecse only which are not capable of receiving the retracted hydranth would also be inconvenient. It is, therefore, the best course to adopt to abandon the use of the term hydrophore altogether. The genus Halecium is usually regarded as distinguished from its allies Dip- lucy filing (Allmau), l-Ji/tIr» zooid which the nematophore envelopes (in the caj,!,-inn obtained by the 'Challenger' were not observed, but the gouothecre of If. /A.r/A, //. dichotomum, II. fastigeatum, II. Jn'iinii and If. cymiforme obtained by the >ame expedition were not in " coppinia " masses. This peculiar grouping of the gonothecse is not, therefore, a character of the genus, but may indicate a method for the future rearrangement of the species into subgeneric groups. HALECIUM ARBOREUM. (Flute IV., figs. 27, 28, 29.) Halefiinn arbmei/m, Alhmin, ' f'li;ilk'iu;vr ' Reports, Vol. XXIII. (.isS.x), \,\. iv., figs. 1-3. Localities.— The species is evidently abundant in McMurdo Bay, extending from shallow water to depths of 130 fins. W.Q., McMurdo Bay, February 20th and 28th, 1902; -20 fms. W.Q., Flagon Point, January 17th and February 23rd, 1903; 10-20 fms. W.Q., No. 6 hole, January 31st, 1903; 130 fms. W.Q., February 21st, 1902; 10 fms. AV.Q., off cable, February 17th, 1904. East End of Barrier, January 29th, 1902; 100 fms. The specimens of this species consist of a number of robust colonies rising to a height of 300 mm. from a thick hydrorhizal plexus. A few small colonies from the east end of the Ice Barrier were found attached to the stems of Plumularia. Hydrosome. — The hydrorhiza is a dense plexus of tubes exhibiting a tendency to be grouped together in polysiphouic bundles. The main stem is a thick polysiphonic hydrocaulus 10 mm. in diameter. The proximal branches are polysiphonic, like the main stem, and anastomose fivrly whenever they come in contact with one another. The distal branches are much more numerous and usually monosiphonic. The monosiphonic branches (fig. 27) alone bear the hydrothecse, but in some cases these branches still bear hydrothecse after the addition of the first few strengthening tubes. o o The ramification of the distal branches is pinnate, and in other parts of the colony it is roughly, but not rigidly, nabellate. The thickness and roughness of the stem and of the principal branches afford admirable support for the hydrorhizae of other hydroids, a list of which will be found on page 1. 2 F 2 SYDNEY J. HICKSON AND F. H. GRAVELY. Up to a height of about 150 mm. the colony consists of only four or five thick (7 mm. in diameter) and occasionally anastomosing stems, bearing a few thinner (3 mm. in diameter) branches which are themselves pinnately branched. Above this region the thick stems branch much more profusely and somewhat pinnately. bearing numerous thinner branches whose method of further ramification is always pinnate. The ultimate branches (hydrocladia) are jointed, the internodes being 0*6-1 * 1 mm. in length and about 0 • 4 mm. in diameter. Each internode bears on one side a single hydrotheca (hydrophore) adnate throughout its whole length, and supporting the base of a hydranth 2 mm. in length (fig. 24, />////.) similar to those of the other parts of the colony, and numerous paired gonothecaa (fig. 29, nit«rctu:uK may serve as a warning that the setting free of the medusa; is not a character that can be used as absolutely diagnostic of a genus when applied to these sub-glacial species. It is interesting to note in this connexion that Mr. Hodgson (12 : p. 397) states that Pliiididhuii medusa} were abundant in McMurdo Bay. CAMPAXULINA A. L<«-/., blastostyle ; *'.j>., chitinous pellicle ; d., dactylozooid ; yph., gonophore ; ylli., gouothcca ; gz., gastrozooid ; he., hydrocaulus ; /irlt., bydrorhiza ; hth., hydrotheca; hyd., hydrantli ; in.., manubrium ; H., node ; nph., nematophore ; op., operculum ; or., ovum ; p., perisare ; /•Ac., rhizocanlua ; sp., sperm ; su.c., sub-umbrella cavity ; /., tentacle ; it., umbrella ; z., zuoid. PLATE I. FIG. 1. — Perigonimus antarctic us growing on Halecium arhoreum (x 2). he. H., hydrocaulus of Halecium arbare um ; hyd., hydrauth of Periijonim its ; f/ph., gonophore of Peru/animus. FIG. '2. — Perigonimus antarcticus $ (x 20). A/7/., hydrorhiza; m., manubrium of gonophore; p., perisarc ; sp., sperm filling the sub-umbrella cavity ; H., umbrella wall. FIG. :'.. — Perigonimus antarcticus 5? showing variability (due to contraction) of form of the hydranths (x 2n). Ac., hydrocaulus; lirh., hydrorhiza; hyd., hydrauth; m., manubrium of •rouoplmiv ; ov., ova embedded in the ectoderm of the manubrium ; si/.c., sub-umbrella cavity ; //., umbrella wall. Fn;. 4. — Eudeudrium insiyne. Hydranth (x :!((). c., collar of deeply staining cells ; j>., perisarc. FII;. 5. -Styliti'tis holer ii (x 3d). Outer region of colony growing on Halecium arboreum ; d., dacty- lozooid ; Ac. H., hydrocaulus of Halecium ; hrh., hydrorhiza ; gz., gastrozooid. FIG. (i. — Stylactis Italeeii ( x 20). Central region of colony growing on Halecium arhoreum ; hi., blasto- style ; bl.f., tentaeulate blastostyle ; gz., gastrozooid ; Ac. H., hydrocaulus of Halecium ; hrh. P. &. C. hydrorhiza: of Perigonimus and Campanularia. PLATE II. FIG. 7. — Hydractinia dendritica, encrusting Halfdum arloreum (x Id). bl., blastostyle ; gph., gonophore ; gz., gastrozooid ; r.sp., ridge-like spine. FIG. 8. — Hydractinia dendritica. Fragment of rhizocanlns (x 20). II., blastostyles ; gph., gonophore; gz., gastrozooid ; rhc., rhizocaulus. FIG. !>. — Hydi-aetinia dendritica (x 2). Young rhizocauline colony developing from the encrusting basal region ; enc. r., encrusting region ; fr. rhc., free rhizocauli. FIG. !U. — Hydractinia dendritica, encrusting Halecium arboreum (x 1). FIG. 10. — Hydractinia dendritica. Part of adult rhizocauline colony (x 1). r/jc., rhizocaulus ; .., zooids. FIG. 11. — Tubularia longstaffi (x 1). yph., gonophores ; ArA., bydrorhiza. FIG. 12.— Tubularia ralphi (x 2). FIG. 13. — Tubularia hodysoni ( x 1). FIG. 14. — Lampra microrhiza (x 1). c.p., chitinous pellicle; gph., gonopliores ; hrh. f., liydrorhizal filaments. PLATE III. FIG. 15. — Lampra pnrvula. Young zooid (x Id). d.t., distal tentacles; Ac., hydrocaulus; hrh. f., hyrdrorhizal filament ; hyd., hydrauth : p.t., proximal tentacles ; /'.:., polyzoan colony to which the zooid is attached. VOL. III. - '• 34 SYDNEY J. HICKSOX AND F. H. GRAVELY. Fro. 1G. — Lampra parvulu. Adult and smaller zooids (x 1). r.p., chitinous pellicle: f.sp., feltwork of sponge-spicules and diatoms in which the basal ends of the zooids are embedded ; i/ph., gonophores. FIG. 17. — Corynidae, sp. B. (x 10). hr.., hydrocanlus ; hrh.f., hydrorhizal filaments; liyd., hydranth. FIG. is. — Mijriothcla ? (x 2). hrh.f., hydrorhizal filaments ; t., tentacles. FIG. 19. — SerttilarMit spiral is. Part of a pinnule ( X 25). fie., acrocyst ; ecf., ectodermal sheath around base of liydranth ; gth., gonotheca ; op., operculnr flaps. FIG. 20. — Sertiilnri'llit xpiralis ( X 25). Part of main axis, showing method of branching; hr., branch ; hth., hydrotheca ; in. a., main axis. FIG. 21. — Sertularella plectilis (x 15). gth., young gonotheca; hyd., hydrauth ; r. hth., reduplicated hydrotheca ; s. hth., simple hydrotheca. FIG. 22. — Dktyocladium fwcum (x 10). /;//*., hydrotheca ; st., stolon helping to bind the colony together by anastomosing with another branch. FIG. 23. — Pltmittlaria gMwlis ?. Central axis and proximal part of hydrocladia (x 20). '., to give greater clearness to the different parts of the gonophore. FIG. 33. — Diagrammatic longitudinal section of male blastostyle of Stylactis halecii (x 50). c.p., collar of perisarc around base of zooid ; ms., inesoglcea ; nc., uematocyst in the ectoderm ; t., tentacle (entirely ectodermal) ; other letters as in fig. 32. FIG. 34. — Diagrammatic longitudinal section of male gonophore of Tubulnria hndjsoni (x 5o). Letters as in figs. 32 and 33. FIG. 35. — Diagrammatic longitudinal section of female gonophore of Lampra pctmula (X 3o). end. H., endoderm of umbrella ; ov., ovum lying amongst the other rounded and deeply staining cells of the cndocodon ; ov. ri/p., ovum rupturing the "umbrella " and protruding part of its substance through to the exterior ; other letters as in figs. 32 and 33. Antarctic (Discovery) Exp Plate I. 3 hyd PERIGONIMUS ANTARCTICUS (l-3), EUDENDRIUM INSIGNE (4), STYLACTI-6 HALECII (5,6). Antarctic (Discove: ^Wt 61. 9 ^J^P , y ' f . HYDRACTINIA DENDRITICA (7-: EULARIA LONG 1 12), T. HODGSONI (13), LAMPRA MICK Ant-. Discove Place III. 18 22 v -- 1 Discove. op. 31. : 32 end.m CAMPANULA ',' ARBOREUM (27-29), OBELIA GENH 1 : III.-TENTACLES OF A SIPHON OPHORE. AMOX an attenuated object wliich was the subject of a good deal of speculation. Almost simultaneously with the discovery of its hydrozoic nature, I received a copy 3 fathoms. It was only liberated with considerable difficulty, and arrived on board in an imperfect condition, and, of course, frozen hard. It was about as stout as an ordinary bootlace, somewhat ragged, and of a light brown colour. I judged it to be very nearly twenty feet in length. It so happened that there was no preservative material available at the time, and as sea-water could not be obtained under half an hour, the heat of the ward-room caused the specimen to disintegrate rapidly, and it was lost. On August 1st, 1902, a stationary trap was hauled at No. 5 hole in 178 fathoms, at a distance of a mile and a half from the ship. On the swabs attached thereto were two specimens of this organism. They lay as tangled masses among the fibres of the swabs, and appeared to be about the same size, or larger, than the original specimen, but stouter and evenly cylindrical throughout. Owing to the hole being choked with ice crystals, no water could be obtained ; all specimens had to be brought to the ship "dry." The temperature at this time was — 50° Fahr., and under these conditions the specimens were lust. ( in I tecember 1st, 1902, at No. 4 hole, the total depth of water being 41 fathoms, a tow-net had been let down to a depth of 8 fathoms. On the line immediately above the tow-net one of these organisms was entangled. As the weather was warm, little * Scotia Collections.— On the Tentacles of an Antarctic Siphonophorc. By John Rennie. D.Sc., University of Aberdeen. 2 (i 2 JOHN RENNIE, D.Sc. below freezing point, and the water clear, it could be roughly examined before removal. The organism appeared to be an inert and delicate structure, about a quarter of an inch in diameter, which appeared to be uniform throughout its entire length, rounded at both ends, translucent and light brown in colour for the most part, though in places almost colourless. This specimen was secured, but in fragments, preserved in picric acid, and transferred to alcohol. Unfortunately the bottle in which it was kept was one of the only two which failed, and some months later was found to be EXPLANATION OP FIGUEES. 1. Piece of Tentacle. (Natural size.) 2. „ , enlarged, showing Stinging Areas, x 18. 3. Transverse section : (a) Ectodermal Canal ; (b) Eiidodermal Canal, x 40. 4. Stinging Areas, showing Cnidoblasts. x 280. 5. (a) Cnidoblast, with coiled lasso. (It) „ , with lasso shot out. x 500. practically dry ; the specimen was then replaced in alcohol and kept under observation. No other specimen was taken, but from the date of its first capture on Lieut. Barne's sounding-line to the close of our stay in McMurdo Bay it occurred on the lines of the nets and traps frequently, probably not less than fifty times. It was usually much attenuated by being drawn somewhat rapidly through the water, and shredded on the iron bar over which the line ran. This last piece of apparatus was an essential, as the line has to be laid straight out on the ice. A wet line at those temperatures can neither be coiled nor wound on a winch. The organism usually TENTACLES OF A SIPHOXOPHORE. 3 occupied from ten to twenty fathoms of line as it was drawn up. No time of the year can be definitely stated as to when it was most abundant. Note by JOHN EEXNIE, D.Sc., University of Aberdeen. The specimens described as " bootlaces " consist of a number of tentacles of a Siphonophore, taken by Mr. Hodgson under the difficulties just described. The state of preservation is not very good, the parts are extremely friable, and break readily on manipulation. It is not possible to tell whether they originally formed one piece* or not, Besides smaller portions, there are nine parts, ranging in length from about 30 cm. to 6 cm., with an almost uniform diameter of S'Gmm. The surface is in colour a dirt}' greyish white, and under a low power is seen to be divided up into definitely marked areas (see figs. 1-5), such as distinguish the tentacles found by the Scottish Antarctic Expedition, and described by me.f Cnidoblasts of large size are present in great abundance upon these areas. They possess a lasso, which is at least nine times the length of the cell, and which is barbed throughout its entire length. Ectodermal and endodermal canals of the ordinary type are present, and no further noteworthy features are observable. These tentacles differ from those of the Scottish Expedition, both in colour and consistency, the latter being brownish and of a markedly gelatinous nature even in their badly preserved parts. They appear to belong to a distinct and otherwise unknown form. * Before being taken from the water the organism was unquestionably in a single piece, and was so whenever it occurred.— T.V.H. t Proc. Royal Physical Society, Ellin. XVI. (1904), p. 25-7. POEIFEKA. BY R. KlRKPATRICK. THK Sponges brought home l>y the 'Discovery' from the Antarctic Region were obtained mostly from two localities, viz., from 183 metres (100 fathoms) off Coulmun Island, about '200 miles north of the Winter Quarters, and from the neighbourhood of the Winter Quarters (Lat. 77° 49' 8., Long. 167° 7' 4" E.), from depths ranging from 9 in. to 3GG in. (5-200 fins.); one specimen, a new species of Hexactinellida, came from (J14 in. (500 fms.) off Mount Erebus, and another, also a new species (if the same group, was dredged from 4G4 in. (254 fms.) when the ship was crossing the Antarctic Circle, on the voyage home ; and, lastly, a few Sponges were dredged near the edge of the great Ice Barrier, some degrees eastward of AVinter Quarters. The specimens were procured by means of dredges of various kinds, such as trawls and D-nets, sometimes with tangles attached. Wherever possible, the apparatus was lowered in open water, but after the ship was frozen in, holes were made in the ice ; and it was necessary to adopt elaborate precautions to prevent the dredges being lost and to enable them to be dragged along the bottom. By these means there were obtained a large number of specimens, which afford testimony to the indefatigable industry and resourcefulness of Mr. T. V. Hodgson, who was in charge of the dredging operations. Mr. Hodgson, in his Preliminary Report on the biological collections (3, p. 397), observes, "A predominant feature in the fauna was the enormous quantity of sponges and sponge debris, anywhere near the 20-fathom line sponges and sponge debris forming the bulk of the haul as a rule." The bulk of the collection so far as concerns the size and number of specimens is made up mainly of Tetractinellida and Hexactinellida. There are fifty-nine specimens of Tetractinellid Sponges, some of them of large size, belonging to four species ; the ' Belgica ' Antarctic Expedition dredging in the neighbourhood of the meridian of 90° W. found none belonging to this group. The Monaxonellida are represented by forty-three species, and the Calcarea by twenty-four species. There are no Keratosa or Horny Sponges. With the exception of two dried specimens and of a few in formalin, the collection is preserved in strong spirit. 2 E. KIEKPATEICK. I.-HEXACTINELLIDA. (7 Plates.) THE Hexactinellid Sponges, comprising thirty-four specimens and sixteen macerated fragments, all belong to one Family, the Rossdlidse. The specimens represent five genera, of which three are new, and ten species, of which eight have not been described before. The following is a list of species with depths and localities :— FAMILY ROSSELLID.E, F. E. SOHULZE. (SUB-FAMILY ROSSELLIN.E, F. E. Schulze.) 1. Hyalascus hodgsoni. Off Mount Terror, 914 metres (500 fathoms). 2. Rossella antarctira Carter. W.Q., 238 m. (130 fins.). 3. Rossella podayrosa. W.Q., 18-55 m. (10-30 fms.). 4. Rossella racovitzw Topsent. W.Q., 18-3(1 m. (10-20 fins.). 5. Rossellu Itexactinophila. Antarctic Circle, Long. 155° 21' E., 404 in. (254 fms.). 6. Aulorossella piloxa. Off Coalman Island, 183 m. (100 fms.). 7. Aulorossella levis. W.Q., 18-325 m. (10-178 fms.). 8. Auloronsella kngstaffi. W.Q., 238 m. (130 fms.). 0. Anaulosoma schuhii. W.Q., 30-75 m., (20-11 fms.). SUB-FAMILY LANUGINELLIN.E, F. E. Schulze. 10. Anoxycalyx ijimai. W.Q., 329 m. (180 fms.). Two species in the above list have been described before : one of these, Rossella untarctica Carter (2, p. 114), was dredged by Sir James Clark Ross in Lat, 74° 30' S. Long. 75° E., 549 m. (300 fms.), during the voyage of discovery to the Antarctic Regions in 1839-43 ; the other, Rossdla racovitzse Topsent (11, p. 33), was obtained in 1897-99 by the ' Belgica ' from Lat, 70°-71° S., Long. 80°-87° W., 450-569 m. (267-310 fms.). To the one species previously known from the Antarctic, the ' Belgica,' dredging in Lat. 70°-71° S., Long. 80°-89° W., added the following nine :- 1. ? GauloplutC'iis sp. 450 in. (240 fms.). 2. Rossella nuda Topsent. 430 m. (235 fuis.). 3. Rossella racovitzw Topsent. 45(i-5(jl) m. (240-311 fms.). 4. Bathydorus spinosus F. E. Schulze. 50'J m. (311 fms.); also from Penguin Island, 2920 m. (1GOO fms.) ['Challenger']. 5. Rhahlocalyptus at/straits Topsent. 450 m. (i. Fnrrea occa (Bowerbank) Carter. 450 in. 7. Eurele yerlachei Topsent. 450-550 m. (240-301 fms.). s. Chonelasma sp. 45o-5on m. (240-273 fms.). 9. Uncinatera plicata Topsunt. 430-50(i m. (235-273 fms.). All of the eighteen Antarctic species belong to the Hexastcrophora, not one representative of the Amphidiscophora having been found hitherto. In connection with bathymetrical distribution it is interesting to note that specimens of four of the species obtained by the 'Discovery ' come from comparatively shallow walcr, from depths ranging from 18-75 m. (10-41 fms.). TTEXACTIXELLIDA. 3 A curious phenomenon remains to In- noticed. On October i'4tli, 1903, Lieutenant Armitage's sledge party found a dried macerated Ilexactincllid Sponge and also tufts of spicules being "blown aliout by the wind amongst the erratics on the ice." The existence of recent Hexactinellid Sponges on the surface of the earth and brought there liy natural agencies is a very unusual occurrence; for, generally, these Sponges live in too deep water to be cast up by .storms. In the present instance, probably the sea bottom was scooped up by ice, and the material afterwards floated up on detached masses of ice. Both the specimen and tufts of spicules belong to a new species, viz.. Aulorossella Ac/*, common in shallow water up to -JO fathoms. ABBREVIATIONS AND EXPLANATIONS. (1) W.Q. moans " Winter Barters." (2) A Unman and an Arabic numeral in brackets mean number of plale and figure ; thus (I. G) means Plate I., fig. G. OBDER HEXACTINELLID A, F. E. SCHULZE. SUB-ORDER HEXASTEROPHORA, F. E. Schulze. FAMILY ROSSELLID.E, F. E. Schulze. SUB-FAMILY ROSSELLIN.E, F. E. Schulze. HYALASCUS, Ijima. HYALASCUS HODGSON i. (Plate III. fig. 1, and Plate IV. figs. 1 a-g.) Sponge an elongated, slightly flattened oval sac, broadest a little above the base, with an oval orifice with thin, soft, felt-like, unarmed edge. Surface with a few small, pointed, tuft-like conuli ; with oxydiactin, and rarely oxypentactin pleuralia. With rounded base provided with short scattered bundles of basalia (probably forming a root-tuft in complete specimens). Gastral membrane continuous (to the naked eye). Autodermalia hexactins, rarely pentactms ; hypodermalia oxypentactins with smooth surface. Gastralia slender hexactins. Intermedia holoxyhexasters,* hemioxyhexasters, rarely monoxyhexasters * ; discohexasters, and microdiscohexasters. Colour (in spirit), pale buff; consistence rather soft and flexible, but firm enough for the walls to be self-supporting when out of spirit. De*rri/if/nn i if the sy/y small densely crowded autodermalia. Ijima (5, p. 90) refers to similar patches on the gastral surface of //. sagamiensis, " due to excessive local accumulations of gastralia." Dredged from 914 metres (500 fathoms) off Mount Erebus. ROSSELLA ANTARCTICA. (Plate L, figs. 1 to 4, and Plate IV., figs. 2a to g, and 3a to k.) 1*7:.' Rossella antarctica, Carter (1, p. 400, pi. xxi.). 1875 „ „ (2, p. 114, pi. x., tig. 4). 18*7 „ F. E. Sdmlze (6, p. !:!'.», pi. lv.). Three specimens of this species were obtained. They were brought up in the same haul from Winter Quarters, No. 10 hole, 130 fms. The specimens show a canals to the primary rays, and the spine-like nature of the secondary rays: — 1'L IV., tig. 2d' "' shows an hexactiu-like uionoxyhexaster with the axial canals extending but a very short distance from the centre, the rest of each ray being solid. I'l. VII., tig. Hi, shows a monodiscohexaster with the axial canals extending only to the end of the basal thick portion of each ray. I'l. IV., tig. 3d" shows three spheroidal reduced hexastcrs in which the primary rays have disappeared as rays, while the secondary ra\s remain as one or more spines, or < spheres, attached to the central sphere, the axial canals being confined to the central node or sphere. I'l. IV., fig. 3d' (on the left edge of the plate) shows a monoxyhcxaster in which one of the six secondary rays is becoming reduced, this being a stage on the way to becoming a spheroidal reduced hexastcr. t The descriptive term " eapitulum " is suggested for the enlargement or swelling at the distal end of the primary rays of calycocomes, aspidoplumicomes, strobilocomcs, mierodiscohcxastcrs, etc. The shape of the " eapitulum" in these spicules calls to mind the receptaculum and eapitulum of the Cornposita:. •2 H 2 f, K. KIRKPATRICK. considerable amount of variation, and will be described separately as A, B, and C. Had they not come from the same spot, I would probably have regarded B and C as representing a variety of the typical form. All the specimens possess a well-developed root-tuft, therein differing from those obtained from Kerguelen and other localities in the Southern Indian Ocean, and from near the mouth of the Rio de la Plata in the South Atlantic. Prof. Schulze mentions in the ' Challenger ' Report (p. 139) that he had never found the loose root-tuft, which Carter represents in his diagrammatic figure (2, pi. x., fig. 4), and he considers this modification in the original specimen to be conditioned by the looser nature of the substratum. Prof. Ijima observes (5, p. 5) that " a case of one and the same Hexactinellid species being firmly fixed when growing on a hard substratum, but producing a root-tuft when living on a soft bottom, has never as yet been shown to exist." The ' Discovery ' and ' Challenger ' specimens of Rossella nnturctica seem to me to furnish instances of specimens of the same species being fixed solidly or by a root-tuft in accordance with the nature of the bottom. In spite of the considerable range of variation in bodily form, mode of fixation and spiculation, the Antarctic and the more northerly forms appear to me to come within the limits of one and the same species, but I regard the latter as belonging to a variety — var. solld/i. The microdiscohexasters, too, are considerably larger in the typical Antarctic specimens than in the northern variety. If the anchor spicule figured by Schulze (6, pi. lv., fig. 12) really belongs to the specimen from which it was obtained, its presence suggests that the sponge, now solidly fixed without a root- tuft, was derived from a form with such an appendage. Specimen A.— (Plate I., fig. 1, and Plate IV., fig. 2 a-g.) This, which is the smallest of the three specimens, closely resembles the original one obtained by Sir James Ross and diagrammatically figured by Carter (2, pi. x., fig. 4). The total length is 7 cm., the body being 4 cm., the root-tuft 2 cm., and the oral fringe nearly 1 cm. in length. The greatest breadth is 3 cm. The velum is about 7 mm. from the surface of the body. Numerous oval or pyriform buds, each about 2 mm. in length, are present amidst the dense tangle of the velum. The orifice is narrow, oval, about 1 cm. in length, and acute-angled at each end. The diactin marginalia surrounding it form a sloping palisade which meets in the middle line above, the inclination increasing from without inwards. The root-tuft, which encloses debris of worm-tubes, fragments of Polyzoa, etc., is formed of pentactins in the shape of four-pronged anchors with thick curved prongs. The surface of the body is level, though here and there small, barely perceptible conuli occur. The skeleton is mainly formed of long wavy bundles of slender diactins. Spicules. — The principalia are long slender diactins, often with roughened, rounded or bulbous ends. There are also parenchyma! regular hexactius (IV., 2a) scattered about. The marginalia are sharp-pointed oxydiactins 1 • 5 cm. long and 160)u, thick. The basalia arc' long, slender, four-pronged anchors 4 cm. in length, with HEXACTINELLIDA. 7 curved prongs 45(J /x in length. The autodermalia (IV., 2 b-b") are hexactins ('Jb1), pentactins (2b), ;iinl rarely stauractins (2b3), each ray being 75 x 1 1 /x, wholly spined, nearly cylindrical, and with blunt end. The pentactins have a well-developed distal spiny knob. The hypodermalia are slender oxypentactius with paratangential rays with roughened surface and with large prickles. These well-known spicules are not figured owing to want of space. The autogastralia (IV., 2c) are large slender hexactins, each ray being 17:5 x 0 jj.. Some of the hexactins, a little below the surface, are very large, with the radial rays (each 252 x 21 JJL) longer than the other four. The intermedia. — The holoxyhexasters (IV., 2d, d1), hemioxyhexasters (IV., 2(T), and inouoxyhexasters (IV., 2da, 2d4), about 164 p in diameter, have very slender roughened rays, the primary rays being very short or almost absent. The calycocomes (IV., 2f) are 80 /x, in diameter, with long tuberculated primary rays, each 22 fj. in length, ending in a solid hemispherical capitulum from which the only slightly divergent secondary rays proceed, presenting, as Carter put it, a dinner-fork-like aspect in optical section. Another kind of calycocome (IV., 2g) has shorter, thicker, and smoother primary rays, a knob-like capitulum, and more divergent secondary rays. Medium-sized holodiscohexasters, like those figured by Schulze (6, pi. lv., fig. 15) do occur, but rarely. Plate IV., Fig. 2e, shows a modified hemidiscohexaster 45 '5 ju in diameter, having bulbous primary rays, and terminal discs little more than a circle of spines. The microdiscohexasters (IV., 2h), 50 /JL in diameter, have long primary rays 10 /x in length, ending in a conical point, thp secondary rays being given off in two circles a little separated from each other. Scattered over the outer surface of the upper part of the specimen are numerous small flattened pyriform buds about 52 mm. in length, each bud being supported on one or two pleuralia which penetrate it. None of the buds are sufficiently developed to show oscule or central cavity. The hypodermal oxypentactins have their paratan- gential rays much more curved than in the adult state, and the prickles are hardly at all developed. The soft tissues appear much contracted by the strong spirit. A section shows an outer trabecular layer surrounding a central mass of choanosome, there being only a slight development of an inner trabecular layer, and that so contracted as to appear solid rather than reticular. Specimen B.— (Plate 1., fig. 2, and pi. IV., fig. 3h.) This is a large spheroidal sponge, 15 '5 cm. in height, with a dense velum resembling a tangled thicket, extending about I'l cm. away from the surface, and with a thick root-tuft. The orifice, which i.s oval and with sharp angles at each end, is 3'7 cm. in length by I '4 cm. in its greatest breadth. The marginalia, projecting about 2 cm., lean towards each other across the orifice, the innermost layer extending almost horizontally across from one side; on a level with the oscule is a depression, looking like a second oscule, but the appearance is due 8 R. KIEKPATRICK. to the presence of a worm-tube in the wall of the sponge, thereby leading to a dis- arrangement of the pleuralia and velum. The gastral cavity is capacious, and is lined by a continuous gastral membrane. The wall of the sponge is about 2 cm. thick. The spicules, with certain exceptions, resemble those of specimen C described below. Specimen C. — (Plate I., figs. 3, 4 and pi. IV., figs. 3a-3l, excepting 3h). This is a remarkable twin specimen, ovate spheroidal in shape, and with two oscules. The height is 14 cm. and width 19 cm. The massive, dense root-tuft is 5'5 cm. in length. The edges of the oscules are slightly inverted, so that the innermost margi- nalia, projecting 2' 5 cm., slope downwards and inwards. A vertical section through the line joining the oscules shows the sponge body, apart from the massive root-tuft, to be somewhat hour-glass-shaped with the long axis horizontal. The common gastral cavity is nearly divided into two by a thick, central, pyramidal boss reaching from floor to roof, but not forming a complete partition. The wall of the sponge attains in one part the great thickness of 3" 8 cm. The gastral surface shows numerous circular orifices, from 1 to 3 mm. in diameter, in this respect differing from other known specimens of this species, in all of which the gastral surface is covered with a continuous layer. The twin condition of the specimen cannot be regarded as one of any specific importance. Among the specimens of It. antarctica obtained by the ' Challenger ' from 274 m. off Kerguelen Island is a twin specimen with a short common base whence spring two thick cylindrical tubes ; the shape somewhat resembles that of a gigantic tuning-fork. The gastral cavities communicate through an oval foramen below, and the gastral membrane is continuous throughout. Spicules of Specimen C.— The principalia are diactins with rounded or bulbous, roughened ends, and large regular hexactins with smooth tapering rays each 640/x in length. The marginalia are smooth, thick, fusiform diactins, about 4 cm. in length, and 270/x, in thickness in the middle. The basalia (IV. 3a, a1) are anchor pentactins with four prongs, usually curved, but sometimes straight. Both in B and C these anchor spicules are present among the hypodernialia some distance above the root-tuft, and some have the prongs anortho- tropal, thus supporting 8chuke's supposition that pentactiu basalia are often modified hypodcr mal pen t ac t i us. The autodermalia (IV. 3b.) are chiefly peutactins with or without a distal knob ; hexactins being fairly common in B, but rare in C. The OXypentactin hypodernialia, as might be expected, are larger than in specimen A, and have thicker rays with longer prickles. The autOgaStralia (IV. 3c) are mainly hexactins with spined, blunt-ended rays, HBXACTINELL1DA. 0 each 83 x 11/x ; in C autogastral pentactins (IV. 3C1) are, in addition to the hexactins, (juite common. ( Mi re-examining (he antogastral hexaetins of A, B, C, T find the differences are not so orcat as is depicted in IV. 2e and IV. 3c. The spienle shown in IV. 2c lias excep- tionally long and slender rays, and that shown in IV. 3c has exceptionally short and blunt rays. In specimen B the rays (20(5 x 15/x) are slender, sharp-pointed and slightly spined. Intermedia. The holoxyhexasters, hemioxyhexasters and monoxyhexasters show a considerable amount of variation and abnormality, especially in the twin specimen C. The Imloxyhrxastrrs and hemioxyhexasters are on an average from 100 to 110/j. in diameter ; fig. 3d shows a small holoxyhexaster (in optical section) only G2/x in diameter. Usually the primary rays are small but distinct. The monoxyhexasters (IV. 3d3'4), 12G/A in diameter, have sharp-pointed secondary rays with rough surface, are broad at the base and tapering to a sharp point. The abnormal spicules figured in fig. 3d6 have the primary rays reduced to a central node or sphere, and the secondary rays to a few spines. In some hexasters (IV. 3e) the secondary rays terminate in two or three sharp prickles. 3d5 shows a stauractin-like monoxyhexaster, 145//, in diameter, the rays having a roughened surface. That these spicules are not young autodermal stauractins is shown by the fact that the axial canals extend only a short distance from the centre. The calycocomes (IV. 3f-h), 80 to 90//, in diameter, show considerable variation, not only in specimens B and C, but also in the same specimen, viz., variation in size, in length and thickness of the primary rays, in the length and degree of divergence of the secondary rays, and in the presence or absence of terminal disks. Fig. 3h, from specimen B, is evidently abnormal ; here some of the secondary rays have fine bifid or trifid terminations. Hemidiscohexasters of medium size (IV. 3e, e1), average about 85ft in diameter ; the rays are sometimes thicker and straighter than is usual in this species. Monodiscohexasters, 90/x in diameter, occur rarely. Prof. Schulzc figures (6, pi. LV., fig. 8) a spicule of this kind— the only one found by him — from a specimen from Kerguelen Island. The microdiscohexasters (IV. 3k), 50;u, in diameter, are mostly similar to those in specimen A, with a narrow conical capitulum, whence two circles of secondary rays originate; some, however, have a more disk-like capitulum (IV. 31); the secondary rays in both kinds are extremely slender, being almost invisible under any object-glass lower than T^ inch. Curiously enough, these rays are much more easily discernible in the younger and less developed specimen A. All from W.Q., June 3rd, 1903. No. 10 hole ; 238 m. (130 fins .). Other specimens have been found at :— Lat. 77i° S., long. 175° W. ; 548 in. (300 fms.) ; Sir J. C. Ross's Expedition. Prince Edward Island, 25G m. (140 fms.); Voy. 'Challenger.' 10 TC. KIRKPATPJCK. s c K H g 63 O H B H '& a o W o W W H O H S O 02 1 . 1 a b2 i cS O ii Tl CO CO rt o . rt S -^ CD r. a 1/s = marked. -t> CO § .3 ^ 1 oi* ^fl *-£s a Ug.8" ce -*i j£ t-l CJ "o E^ 9 o tT o 13 a ^0) i •* - a <5 "3 .2 .^i "^ ''s _§ K NI a g H oi £ '1 -*j a §^ O C5 10 CO 3 .•*5 g ^3 2 „• 1? PH ^ ^ 0 ,—r "ce a «-»« M" OJ o "co ie S 3 o B ce ^ ^ a j s-g s CJ O3 ^ o; — • O £, S •^ . CJ t_, o-. '"^ ^~ ^_, -u o: •^ ->~s .- .J s utheru Indian ' Challenger J?J Absent. c3 s "3 1 1 co O Hexactins, ,3 -t- frf 0 ^g *rl 5 o S tc 00 00* ^ on,wifcbslend Diameter, 40 & !i Pn -§ 2 N c w 5 ^ '^ S ^ o ^ •r-l ^H ^O ^^ o " ° PH ^ P O o t* 0 CJ "§ J -*-1 o CO a S -2 bo >•» a g S"3 'oS M t* ^-< ^ ^~i j_> JH o EQ ft o" a C3 pq Spheroidal, igle or Double. Present. 3 -t-i ! O) PH >-, 1 's g s fc^ CO J1 > .•S • CO > ^3 a S'-S S^ § cxactins in B. is and Pentact: o ,;, [3 la .a -^ .-£ £"-J S S % 02 —i -1 s ^ ^a o •" " tT cc' 'cS ^ a s S "^ 10 I" 03 a a CJ bo 1 111 W-H o C3 . S |r>^ •^ 3 ^ r— - •? ~ a i 1 1 » . J > « 1 r— •>, •73 ^ bed by Carter, , ' Discovery.' HJ CD 3 '-4J & 0> O -= rn' §§d ^|l •33^ lib ^3 5 P DO .5 -+o f-< r-^ !3 CO P-t?^3 •4-3 V. 'P > 03 JO Sa^ s S 5 c3 cu •^ ^3 • tU3 •^ ri 3 „ to 8 •» .> ' ^J ?3 O QN r^ f^ ^2 '*^ t^ t—i 1 o 0.^ a -^ o ^- -d i o irnen descri Specimen A o| CD CO FH PH 3 PH >-, 8 ctins with actius not ,0'S CO cd S ffi CB "H P< PH ^ S f^ ^N > S • • • • • • • • CO a" 2 •s PH oot-tuft CO "a 0 CJ 1 ^ utodermalia . utogastralia . £ -2 § 1 CO O a o § iscohexasters . icrodiscohexash S PM 1/2 < a c3 cu a o> 1 1 1'.X. \CTIXKLLI DA. 11 Possession Island, 384 111. (210 fins.) ; Voy. 'Challenger.' Kerguclen Island, 274 m. (150 fms.) ; \ny. ' (Challenger.1 East of Buenos Ayres, 1097 in. (600 fms.) ; Voy. ' Challenger.' ROSSELLA PODAGROSA. (Plate III, figs. 2, 3, and Plate V., figs, la-m.) Sponge cylindro-eonic, broadest about the middle, with wide, oval, thin-edged orifice, armed with upright marginalia ; the walls thick and firm, with a well-developed root-tuft, composed of diactius and of oxypentactins of the same character as those of the velum. With a velum about 5 cm. from the surface ; with buds of considerable size, solidly attached to the parent by a broad base. The hypodermalia oxypentactins with rough or smooth rays, without prickles. The calycocomes with relatively short primary rays ; discohexasters with long secondary rays. There are ten specimens of this species, one of large size, four of medium size, and five small ones, some of which are probably detached buds. All the larger and three of the smallest specimens possess relatively large buds, with oscule and gastral cavity, and fixed by a broad base ; compared with these, the buds on one of the specimens of fi. "i/furcficn (see page 7) are very small, being only 2 mm. in diameter, and detached from the main body, though still adherent to the pleuralia. The largest specimen (PI. III., fig. 2) is 20 cm. in length, and 8'5 cm. in greatest breadth ; the orifice is 2 • 5 x 2 cm. in diameter ; the walls attain a thickness of 2 • 5 cm. Two buds and the scar of a third are present on the outer wall. Beneath the fine, gauze-like dermal layer are seen the round openings of the ostia from • 5 to 2 mm. in diameter. The diactin marginalia project about 1'8 cm. The root-tuft is about 3*5 cm. in length. A few slender diactin pleuralia project a little above the general velar surface. The gastral membrane, which forms a continuous, finely pilose layer, with a sharply-defined circular rim a little below the edge of the orifice, roofs over the openings of the postica with a fine, sieve-like network, the meshes of which are formed of bundles ofdiactins coven-d with autogastral hexactins. In one specimen the lower part of the gastral membrane is cavernous. In all but the smallest specimens the central cavity is deep, but in the latter it only extends to half the length of the sponge body. The skeleton is mainly formed of bundles of diactius with a few large hexactins. The spicules. Principalia. The long diactins mostly smooth, or only very faintly roughened near the ends, usually straight, tapering very gradually to slender, sharp points, a large spicule being 8'25x '054 mm. Hexactins of two kinds, either regular with thickly spined rays, each 380 X 10/Lt (V. Ib), or with the rays nearly smooth, and with the odd pair of rays (each 1500 X 45/x) equal or unequal, and longer than the other four (V. la). VOL. III. 2 I 12 R. KIRK PATRICK. The autodermalia ( V. lc) are pentactins with or without a distal knob, with all the rays (each 180 x 13/t in length) tapering and wholly spined. Hexactins occur, but rarely. The hypodermalia (V. Id-cF) (pleuralia and basalia) are oxypentactins with rough or smooth rays, orthotropal or anorthotropal, the average length of a paratangential being 1660 x 50/i. The autogastralia (V. le) are hexactius 266 x 12ju, and closely spined. The intermedia are holoxyhexasters (rare), hemioxyhexasters (V. If, f1), and abundant monoxyhexasters (V. If2, f3), about 169/x, in diameter. The ealycocomes (V. Ig, g1) are 226/x, in diameter. The primary rays are only 8/u, in length ; the capitulum is 14'5/A in length and 22/A in breadth; the secondary rays, 3 to 5 in number, are thick, and either without any terminal knob, or with a very small one. Fig. Ih, a calycocome, with long primary rays, and without terminal disks, is only 87/A in diameter, and is probably immature. The discohexasters (V. Ik) are of large size, averaging 110/x. in diameter; the primary rays (each 4'5/A in length) terminate in two to four long, disk-tipped secondary rays. Fig. 11 shows a monodiscohexaster 120/A in diameter. The microdiscohexasters (V. 1m) are 5 I/A in diameter ; the primary rays, each 7/j. in length, terminate in a convex disk-shaped capitulum, from the distal surface of which rays two lengths are given off, the longer rays having larger disks. Rossella podagrosa differs from R. antarctica in that the hypodermal oxypentactins are without prickles ; secondly, the basalia resemble the pleuralia, whereas in R. (iiifiirctica the basalia are anchor-like ; further, the ealycocomes of the new species have very short primary rays ; and lastly, the buds are entirely different in the two species. Rossella nuda Topsent, has no velum. Rossella racomtzce Topsent, is likewise without a velum, and its surface is covered with conules. Rossella hexactinophila, a new species about to be described, closely resembles R. podagrosa, but is distinguished by its hexactin autodermalia, and by the different shape and larger size of the ealycocomes ; also its oxyhexasters have more slender rays. All specimens were obtained from Winter Quarters by means of the D-uet. (1) No. 104, Hut Point, September 24, 1902, 26 m. (14 fathoms) ; (2) Nos. 118, 120, Hut Point, November 13, 1902, 46m. (25 fathoms) ; (3) No. 137, Flagon Point, January 17, 1903, 18-36 m. (10-20 fathoms) ; (4) No. 139, January 23, 1903, 18-36 m. ; (5) No. 239, 12 hole, 46-55 m. (25-30 fathoms). ROSSELLA HEXACTINOPHILA. (Plate III., fig. 4, and Plate VI., figs, la-g.) Sponge forming an elongated oval flattened sack with a sharp-edged oval orifice provided with marginalia. With a velum ; and with a root-tuft about 2 cm. in length mainly composed of oxypentactins resembling those of the velum. IIKXACTINELLIDA. 13 Autodermalia hexactins; oxypentactine hypodermalia witli rougli or smooth surface and without prickles ; oxyhexasters with extremely slender rays. The single specimen representing the al>ove species is in a bad state of preserva- tion, the five half-macerated fragments of grayish colour being saturated with mud. Mr. Hodgson gives the information that on the return voyage the trawl was put overboard and dragged for some distance over a dead level bottom of mud, but that at one spot the trawl passed over a patch of stones dropped by an iceberg. This would account for the condition of the specimen. With some difficulty the fragments were pieced together in the manner shown on PI. III., fig. 4 ; there was no doubt about the base with its small but indubitable root-tuft, nor about the oscular end, but possibly a fragment may be missing from the intervening part ; enough remains, however, to show that the sponge was narrow at the orifice and broader at the lower end than above. The specimen, as made up, is 16 cm. in length, and 5 cm. in breadth below the middle. The orifice, which is 1 • 5 cm. in diameter, is partly surrounded by diactin marginalia projecting about 1 • 5 cm. The root-tuft is formed of dense tufts of basalia caked with mud at the ends. The velum has been mostly rubbed away ; but patches of it exist, especially in the fragment bearing the oscule. The gastral membrane is continuous. Skeleton. — The framework is formed of bundles of thin slender diactins. Spicilles. — The principalia arc diactins very long and slender, averaging 3500 x l'5/i, mostly entirely smooth, and with sharp-pointed ends, though some are slightly roughened at the ends. The autodermalia (VI. la) are hexactins, with rather sharp-pointed rays each 154 x 12/t, and spined throughout ; the hexactins give a pilose appearance to the surface, especially when viewed under a lens. The hypodermalia are oxypentactins, orthotropal, and mostly with straight smooth rays, each about 900 x 20/x ; others are larger, 1000 x 25/x (VI. lb, b1.), with slightly curved wavy rays. The autogastralia (VI, lc) arc hexactins, considerably larger than the auto- dermalia, each ray being 319/x in length, and 11'25/A in breadth at the base, tapering to a sharp point, and only sparsely spined. The intermedia include holoxyhexasters (VI. Id), hemioxyhexasters (VI. Id1), and only rarely monoxyhexasters (VI. Id2), about 110-125//, in diameter; the primary rays are 8-1 0/x in length ; and the secondary rays are extremely slender. The calcycocomes (VI. le), 426/x in diameter, have short primary rays, 13/A in length, continuing each into a long solid capitulum 40/x in length and 16//, in breadth, whence originates a circle of eight to ten finely spined knob-tipped secondary rays. The holodiscohexasters (VI. If, f) of medium size, 125/z in diameter, with short primary rays dividing into four or five disk-tipped secondary rays, occur only rarely. The niicrodiscohexasters (VI. Ig), 48p, in diameter, have their primary rays, •2 i 2 14 R. KIRKPATRICK. 7/i in length, each ending in a convex disk-shaped capitulum, from which arises a circle of disk-tipped secondary rays in two lengths. The new species comes very near to R. pi>-<>*n*/////».w/,v//.v) init^iil.-urii. The specimen is badly preserved, and patches of dermal membrane remain only here and there; but in these patches, and beneath the autodermalia, there are hypodermal pcntactins with orthotropal smooth paratangcntial rays. IVof. Ijima himself says (5, p. 109) : " If A. inifxiikiirii were only provided with pontactiiiic hypodermalia 1 should have no hesitation in referring it to Scyphidium," Among the autodermal 16 It. KIRKPATKK'K. stauractins and pentactins are peculiar pentactins with very short, closely-spilled paratangential rays and a long, smooth proximal ray ; the proximal ray of the ordinary autodermal pentactins is thick and closely spined in its whole length. It is possible that the specimen O.C. 4399 in the British Museum is not specifically identical with the type specimen of S. mitsukurii Ij. in Tokyo. Aulorossella includes three species, all new, collected by the ' Discovery ' in the Antarctic Region, viz., Aulorossella pilosa, Aulorossella levis, Aulorossella, longstaffi. AULOROSSELLA PILOSA. (Plate II., fig. 1, and Plate VI. figs. 2-2k.) Sponge in form of an oval slightly compressed sack, having an oval orifice with thin unarmed margin, the wall provided with large sharp-pointed conuli mostly with long tufts of diactin and, rarely, anchor-like pentactin pleuralia. Gastral cavity deep, and with a continuous finely pilose surface. With a dense, massive root-tuft composed of diactins and anchor-like pentactins. The intermedia include holoxyhexasters — a form in which each primary ray ends in four or five secondary rays being especially abundant — hemioxyhexasters and, rarely, monoxyhexasters. There are three specimens of this species, all about the same size. The largest is 14 cm. in total height, and 9x6 cm. in diameters of the body about the middle ; the pleuralia extend 3 ' 5 cm. from the surface. The body-wall attains a thickness of 2 cm., and the conuli a height of 7 mm. The dermal surface shows a fine lace-like network beneath which are seen the openings of the ostia. The gastral surface (VI. 2) has a finely pilose appearance when viewed laterally, and feels rough, these characters distinguishing the species from the nearly related Aulorossella levis, which has a smooth gastral surface. The surface is finely reticulate, the meshes being '2 to '3 mm. in diameter and • 2 mm. in depth ; the meshes are formed of strands of hypogastral diactins, bristling with hexactins ; about six meshes stretch over -each of the postica. Skeleton. The framework is made up of bundles of diactins ; beneath the dermal and gastral surfaces are numerous thick curved isolated diactins roughened at the ends ; medium-sized parenchymal hexactins occur only rarely. Spicules. The principalia are diactins varying greatly in length and diameter ; they attenuate very gradually to roughened, blunt-pointed ends. The ailtodermalia (VI. 2b) are pentactins with the rays straight, thickly spined, and diminishing gradually to a thick, blunt end ; the paratangential rays are each 131 x 1 Sn in diameter, and slightly bent downwards towards the odd proximal ray. The hypodermalia are pentactins (VI. 2c) with smooth, slightly curved paratangential rays, each 320 x 40/i, making an angle of 70° to 80° with the shaft ; a distal knob or swelling may or may not be present ; the odd proximal ray is 2400ya in BEXACTINELLIDA. 17 length. Sometimes these spicules are found among the diactin pleuralia projecting far beyond the surface, but usually they are situated beneath the autodermal prnlactins, either near the surface or concealed amidst bundles of pleuralia. The anchor-like basalia (VI. 2a) have four thick, straight prongs, 560 X 80/i, sharply bent, so as to form an angle of about 35° with the shaft. The autOgastralia are completely spined hexactins, each ray being 140 X 1'2/a. The intermedia. The oxyhexasters vary from 50 to 80/x in diameter; the commonest form is a holoxyhexaster, with principal rays 8-1 0/x, each ending in four straight, sharp-pointed secondary rays (VI. 2d) ; VI. 2d* shows a variety with curved secondary rays. Hemioxyhexasters in various grades occur, but are not so abundant as the first kind ; monoxyhexasters are very rare. Fig. VI. 2d2 shows a micro- oxyhexaster 22 • 8/u. in diameter, with thick club-like primary rays, each ending in three prickles. The ealycocomes (VI. 2c, e1) average about 130/x in diameter, the primary rays being trumpet-shaped, slender at their origin, and expanding gradually up to a disk- shaped capitulum ; the secondary rays vary in number from three to six. Fig. 2g shows a calycocome with the terminal rays curving in at their extremities. Fig. 2f shows a portion of a larger calycocome, 210/i in diameter, with a cylindrical capitulum partly embraced by the bases of the secondary rays ; an axial canal extends about half-way into each capitulum. Holodiscohexasters (VI. 2h), 94/Lt in diameter, with short, slender, bifurcated primary rays, occur only rarely. The microdiscohexasters (VI. 2k) are 34/j. in diameter ; each primary ray ends in a sharp-pointed, conical capitulum. Dredged from 18.3 m. (100 fms.) off Coulman Island. AULOROSSELLA LEVIS. (Plate II., figs. 2, 3, and Plate VI., figs. 3-3h.) Sponge sack-shaped, with an oval orifice with thin unarmed edge. With conules mostly tufted with pleuralia. Root-tuft formed of a compact mass of tufts of basalia. Central cavity deep and spacious. Gastral wall smooth, showing sieve-like groups of openings. Autodermalia pentactins and (rarely) stauractins, autogastralia peutactins, and to a less extent hexactins. Intermedia including, among other kinds, numerous hcmioxyhexasters and monoxyhexasters. There are four specimens of this species, one large one of pale yellow colour (A) in spirit, selected as the type, another (B) much larger, dried, and of dark brown colour, and two small ones (C, D), in spirit. The dimensions, in centimetres, of specimen A are as follows: — height, 20; root- tuft, 5 ; diameters in median horizontal plane, 12 x 10 ; orifice, 3'5 x 2; depth of central cavity, 11 ; thickness of wall, 3 ; height of cones, 1 ; length of pleuralia from surface of sponge, 3. 18 R. KIRKPATEICK. Specimen B is 27 cm. iu height and 32 • 5 cm. iu diameter ; the colour is now dark brown, but Mr. Hodgson states that it was pale yellow when captured ; many of the conules form large, thick, thumb-like projections. The larger of the two smallest specimens (II. 3) is 3 cm. in height and 2'2 cm. in width, the total height and length, including the pleuralia, being 7 cm. Mr. Hodgson informs me that, on one occasion, he hauled up from 228 m. (125 fms.), No. G hole, a huge specimen, apparently of this species, 2 feet in height and 18 inches in diameter, but in spite of desperate efforts to secure it, resulting in his arms becoming like a pincushion, the specimen fell back into the water and was lost. The dermal surface shows a fine network in which larger and deeper meshes formed by strands of hypodermal diactius are filled in by much finer square meshes formed by the autodermal pentactins. The gastral membrane (VI. 3) is smooth and shows sieve-like groups of small orifices, which are much larger than those of A. pilosn. The membrane is supported by bundles of hypogastral diactius which form a network with large meshes ; usually in each mesh there is one large oval orifice, • 5 to 1 mm. in long diameter, with a sharply- defined thin membranous edge. The sieve-like groups of orifices are separated from each other by unperforated areas or zones, which are sometimes of considerable extent in the upper part of the central cavity. Skeleton. The skeletal framework is constructed of bundles of diactius, and of large regular hexactins, which latter are especially abundant in specimen B. Spicules. The diactin principalia are very long and have their ends either rough or smooth, and sharply pointed (more so than those of A. pilosa). The regular hexactins (VI. 3a) have thick rays each 060 x 90/i, smooth or rough at the ends; many of these spicules are abnormal in having their " paratangential " rays curved and bent away from the normal plane like the ribs of an umbrella. The pleuralia are usually diactins ; a few anchor pentactins occur in the larger, but many in the smaller specimens. The basalia are peutactins, which attain a length of 10 cm. (VI. 3b), and have very stout prongs, 125/^ in thickness at the base. The autodermalia (VI. 3d) are pentactius, with wholly spiued rays ; each tangential ray, 113 x 17/^, tapers slightly. The hypodermal oxypentactins (VI. c3) are grapnel-like ; they are usually found entirely below the surface of the couules, but there are only a few in each conule. Sometimes they project outside among the pleuralia. The autogastralia are chiefly pentactins (VI. 3d1), each ray being 150 x 18/A and wholly spiued ; many hexactius, slightly smaller than the peutactins, also occur ; at the nodes of the hypogastral network there is usually a hexactin about twice the size of the autogastral hexactin and with the rays smooth at their bases. The intermedia. Oxyhexasters. Holoxyhexasters are very rare. Hemioxy- hexusters (VI. 3c, e1) are 120/* in diameter, and with almost aborted primary rays. HKXA;, hall ; o-w^a, body. HEXACTINELLIDA. 21 without hypoderrnal pentactins. Aulnc/mnc, which lias an everted gastral surface, differs from the new genus in 1 icing stalked, and in possessing only one kind of discohexaster.* ANAULOSOMA SCHULZII. (Plate III., tigs. 5, G, and Plate V., fig. 2 a-m). Sponge shaped somewhat like a molar tooth, with rounded or carinated mammilla} at the lower end, and with a free gastral surface at the upper end. Surface smooth, without pleuralia, with a few diactin marginalia at the junction of the dermal and gastral surfaces. With a few very small tufts of diactin basalia extending downwards from the mammillae. Principalia, bundles of diactins, also hexactins, pentactins, stauractins, and tauactins. Autodermalia, pentactins ; hypodermalia diactins in bundles forming a network. Autogastralia, pentactins, with a few hexactins. There are two specimens (A, C) and two fragments (B, D) of this sponge. Specimen A (III, 5), the type, from McMurdo Bay, is 6'5 cm. in height, 4 '5 cm. in width, and 3 • 3 cm. in thickness. The texture of the sponge is loose. The thin felt-like gastral surface, with several thin-edged exhalant orifices, is easily distinguishable from the lace- like dermal surface, the two being separated by a sharp edge. The oval gastral surface, 5x3 cm., which occupies the whole upper end of the sponge, slopes down- wards a little ; the largest of the " oscules " is oval, and 1 x • 5 cm. in diameter ; the walls of the large canal into which it leads are lined simply with scattered canalaria in the form of oxyhexasters. The autogastralia are pentactins, and rarely hexactins. Two or three deeply curved diactins are present on or near the gastral margin, but it is doubtful whether they are really marginalia, or, indeed, whether they belong to the specimen at all. The lower end of the sponge is prolonged into two rounded extensions, each with a small tuft of basalia. The small specimen C (III. 6) is somewhat wedge-shaped, the inferior end narrowino- to a ridge, with a small tuft of basalia projecting obliquely downwards and outwards from only one of the ends of the ridge. The upper end, or gastral surface, 1 • 1 cm. in diameter, is in the form of a small circular area, with one small circular orifice (1 '5 mm. in diameter) of an exhalant canal. Round the margin is a circle of small diactin marginalia projecting about G mm. The two fragments (B, U) are the lower halves of broken specimens ; in them the broken surface shows the openings of numerous canals passing vertically upwards from the base. In A>K'(iili'x»iii'i schulzil there is a marked difference in the appearance of the dermal and gastral surfaces, the former showing a fine lace-like rcticulum perceptible to the naked eye, while the latter has an opaque, felt-like appearance. This difference is chiefly due to the arrangement of the hypodermal skeleton. In the dermal region * I have recently found microdiscohexasters in Aulochone (Cratcromorpha) lanJcestcri Kirkp. from South Africa. These spicules escaped my notice when I first described the sponge (Ann. Mag. N.H. (7) VII., 1901, p. 457). 2 K 2 22 R. KIRKPATRICK. there is the extremely fine square-meshed reticulum formed by the tangential rays of the autodermal pentactins. Beneath this are subdermal spaces separated l>y the proximal rays of the pentactins from the hypodermal network with its much larger triangular or trapezoidal meshes. The strands of the hypodermal network are formed of straight tangentially arranged bundles of rather thick diactins. The gastral region, on the other hand, is without subgastral network and spaces, and the bundles of diactin principalia are not distinguishable from those of the rest of the parenchyma. Canal- System and Soft Tissues. — The main exhalant canals run vertically upwards from base to summit, receiving lateral branches in their course. A section shows circles of the flagellated chambers opening into the finer canals. The subdermal trabecular network, and the lining of many of the exhalant canals, are crowded with masses of knolleu-thesocytes, each thesocyte being about 8-lOju, in diameter. In unstained balsam preparations these masses of thesocytes are clearly distinguished by their dark yellow colour ; further, they take a deeper stain with borax carmine than do the rest of the sponge tissues. The skeleton is formed mainly of bundles of diactins and of separate large hexactins, pentactins, stauractius, and tauactins. Spicules. — The principalia are diactins which vary considerably in length and thickness, the average kind being about 7560 x 22yu,, tapering to fine points and spiued at the extremities. The spicules, which, in specimen A, are regarded as possible marginalia, are in the form of two or three long curved diactins about 5 cm. in length. They have become misplaced, and possibly may not belong to the sponge. The delicate marginalia in specimen C project about 6 mm., and are about 13 mm. in length. The little tufts of diactin basalia are about 2 • 5 cm. in length. The large regular hexactins (V. 2a) have rays 800 x 60/u., slightly spined at the ends ; large pentactins, stauractins, and tauactins (V. 2b, c, d) also are present. The autodermalia (V. 2e) are pentactins with rays 172 x 24'5/x, closely spiued. Young pentactius with fine, smooth, sharp rays occur both in the dermal and gastral layers. The autOgastralia are mostly pentactins similar to the autodermalia ; a few small regular hexactins also occur, especially in specimen C. Plate V., figs. 2f-2f, shows several modified hexactins and a peutactin from the region round the single exhalant orifice in specimen C. The intermedia. Oxyhexasters. Holoxyhexasters (V. 2g), 197/x,, with bifurcate primary rays, short or almost absent, are not uncommon ; a kind (V. 2g1), 86/u., in which each primary ray ends in a disk, whence five to six sharp-pointed secondary rays diverge, occurs less frequently. Hemioxyhexasters (V. 2g2), about 180/*, are abundant; and monoxyhexasters (V. 2g3), also about 180/x in diameter, occur, but rarely; fig. 2g2 shows a hemi- oxyhexaster in which one of the secondary rays has a trifid termination. (The small " 2 " of 2g2 has been omitted in the plate.) HEXACTINELLIDA. 23 The calycocomes (V. 2h, li1) arc, on an average, about '22~)/z in diameter, the primary rays being iy in length; earh capitulum, 6'75/i in length and 14'5/A in l>readth, ends in two to four roughened secondary rays tipped with button-like disks. Ilemidiscohcxasters (V. '2k, k1), lOOju. in diameter, occur but rarely ; the primary rays end in one to three secondary rays tipped with disks having four to six long recurved teeth. Fig. 21 shows an exceptional form, 9 I/A in diameter, with thick primary and secondary rays, the latter again dividing into two or three short branches. The microdiscohexasters (V. 2m) are 43/x. in diameter, with primary rays 5'5/j. in length, and with a convex capitulum, whence about six disk-tipped secondary rays arise. Winter Quarters : (1) one specimen (A), the type, and a fragment (B), February 28, 1902, McMurdo Bay, 36 m. (20 fms.) ; (2) a small specimen (C), No. 4 hole, January 30, 1902, 75 m. (41 fms.) ; (3) a fragment (D), No. 12 hole, September 8, 1903, 45-55 m. (25-30 fms.). SUB-FAMILY LANUGINELLINVE. ANOXYCALYX. LanuginellintB without Oxyhexasters, with Graphioconies. ANOXYCALYX IJIMAI. (Plate III., fig. 7, and Plate VII., figs. 2-2g\) Sponge in form of a small compressed pyriform sack, with the surface studded with small conules and small flattened pyriform buds. With slender tufts of long fine diactin pleuralia and basalia. The orifice narrow and oval, with a plain rim, and without marginalia. Autodermalia stauractins (mainly) and pentactins, with the odd ray proximal, more rarely tauactins and angular diactins ; hypodermal pentactins confined to the conules ; autogastralia hexactins, with large microdiscohexasters, with graphiocomes, and very large strobilocomes. The largest of the three small specimens is 2 • 2 cm. in the length of the body, and 7 '5 cm. in total length, i.e., including the pleuralia; the greatest width is 1*7 cm. and the thickness 7 mm. ; the slit-like orifice is 4 mm. in width. The largest buds attain a length of 2 mm. o The Skeleton is mainly formed of bundles of diactins. Spicules. The diactin principalia of the bundles are very slender, wavy, tapering to fine points, and roughened at the ends ; a much thicker kind are isolated, or with slender comitalia. PI. VII., fig. 2a, shows a parenchymal triactiu X 150. The slender wavy pleuralia attain a length of 5 cm. The autodermalia are chiefiy stauractins (VII. 2b), with each ray 234 x 12/x, slightly spined. curved inwards, rounded at the end ; occasionally these spicules have thick club-like rays (VII. 2b4). 24 E. KIRKPATRICK. The autodermal pentactins (VII. 2b!) are fairly numerous ; the odd proximal ray is spined. Fig. 2b2 shows a tauactin. Tlie rays of the curious angular diactins (VII., 2l>3) form an angle of GO0. The hypodermalia are pentactius (VII. 2c) with long, deeply-curved paratan- gential rays 1240 X 55p, tapering to a sharp point. In one or two instances these spicules project out a small distance, and might be regarded as basalia. The autOgastralia (VII. 2d) are hexactins with slender, sparse! y-spined cylindrical rays, each 188 x 5'6/z,. Intermedia. The strobilocomes (VII. 2f, f1) are 175/x, in diameter; each primary ray (13'5/A in length) ends in a cone or strobilus rounded at the distal end, and giving off a series of four verticils of long slender S-shaped rays, each tipped with a toothed disk ; the verticils increase in length from below upwards, the lowest and outermost being the shortest, and the highest and innermost the longest. The plumes of the secondary rays are more loosely tufted than is the case in most other species, where the rays of the verticils and the verticils themselves are more closely packed. The graphiocomes (VII. 2e, e1) are 150ju in diameter ; each primary ray is 7 '25/A in length and ends in a broad disk, from the whole distal convex surface of which a diverging tuft of fine raphide-like rays is given off. The microdiscohexasters (VII. 2g, g1) are of large size, being GOju in diameter ; the primary rays end in a circle of disk-tipped secondary rays surrounding a central cone continued into a ray ending in a disk. The new genus is near to Lopliocalyx, but differs from it and from other genera of LanugineUinse in having no oxyhexasters. PI. VII., fig. 2, shows a thin section of one of the largest buds, which has an oscule and central cavity. The section has been made in a direction slightly oblique to the long axis, and shows the convex outer ends of the flagellated chambers ; although several of these outer ends have been cut through, the artist has put them in, the figure being a combination one, and, I fear, slightly diagrammatic. W.Q., January 2, 1904. No. 14 Hole. 329m. (180 fins.). INDEX OF MEMOIRS REFERRED TO IN THE REPORT ON THE HEXACTINELLIDA. 1. CARTER, H. J. — " On two new Sponges from the Antarctic Sea . . . ." Ann. and Mag. Nat. Hist., 1872 (4) ix., p. 4(iH. 2. CARTER, H. .!.— " On the Genus Rossella . . . ." Ann. and Mag. Nat. Hist., 1875 (4) xv., p. 113. 3. HODGSON, T. V. — The Geoi/raphical Journal, April, 1905. 4. IJIMA, I.— "Studies on the Hexactinellida." Contribution iii. Journ. Coll. Sci., Tokyo, 1903, vol. xviii., art. 1. 5. IJIMA, I. — "Studies on the Hexactinellida." Contribution iv. Journ. Coll. Sci., Tokyo, 1904, vol. xviii., art. 7 (RossellklicJ). 6. SCHULZE, F. E. — 'Challenger' Report on Hexactinellida, II EX. UTIXELLIDA. 25 7. SCHULZE, F. E. — Amerikanische Hexaetinelliden . . . der Albatross-Expedition. 4°. Jena, 1809. 8. SCHULZE, F. E. — "An account of the Indian Triaxonia collected by the ... 'Investigator.'" Translated by R. von Lendenfeld. Calcutta, 1002. 9. SCHULZE, F. E. — " Gaulophacus arctic us und Calycosoma gracile." Ablmnd. Konigl. preuss. Akad. Wiss. 1003. 10. SCHULZE, F.'E. — ""\Viss.ErgebnisscderDeutschenTiefseeExpn. . . . 'Valdivia.'" Hexactinellida, 1904. 11. TOPSEXT, E. — "Notice prcliminaire sur les Epongesde 1'expedition antarctiijue Beige." Arch. Zool. exp. et gen., 1001 (scr. 3), vol. ix. 12. TOPSENT, E.— " Resultats du Voyage du S.Y. ' Belgica ' in 1807-00." Spongiaires. 1902. PLATE I. FIG. 1. — Rossella antarctica Carter, Specimen A. Nat. size. (Page 5.) FIG. 2. — Rossella antarctica, Specimen B. § nat. size. (Page 7.) FIG. 3. — Rossella antarctica, Specimen C, vertical section. £ nat. size. (Page S.) FIG. 4. — Rossella antarctica, Specimen C, vertical section showing the other half. -/V nat. size. I . Antarctic (Discovery) Exp. Sponges PI. 1 Phot. Macbeth Imp PLATE II. Fn;. 1. — Aidornssella pilosa. Nat. size. (Page Hi.) FIG. 2. — Aulnroxsella lev-is, i nat. size. (Page 17.) FIG. 3. — Aidorossella lens, a young specimen. Nat. size. Fia. 4. — Aidorossella longstnffi. Nat. size. (Page I'.i.) Antarctic (Discovery) Exp. Sponges PI. 2 Highley Phot. Macbeth Imp PLATE III. l. — Hyalascm hodysoni, § nut. size. (Page :1.) Fir;. 2. — Rnasi'l/,/ /KI,///I/,;HSI/.. -A- nat, size. (Page 11.) FIG. 3. — Rostr/ln ,111,/,/,/riixii. another specimen. § nat. size. Fifi. i.—Rossr/lii Inwtitinjilrila. § nat. size. (Page 12.) FIG. 5. — Anaitlosoiini »rliul-ii. Xat. size. (Page- 21.) FIG. (j.—Anaulosoma s<-huhii, another specimen. Xat. size. FIG. l.—Ano.ri/i;dii.i ijimm. Nat. size. (Page 23.) Antarctic (Discovery) Exp. Sponges PI. 3 Highley Phot. Macbeth Imp PLATE IV. FIG. lar-ff. — Hyalasctis hodgsoni. Spicules. (Page 4.) FIG. la. — Autodermal hexactin. (x Kin.) FIG. li. — Autodermal pentactin. (x 100.) FIG. Ic, c1, c2.— Modified autodermalia. (x 160.) FIG. Id, Id1. — Hypodermal oxypentactins. ( X 50.) FIG. Id-.— Autogastral hexactin. (x 160.) FIG. le. — Holoxyhexaster. ( X 240.) FIG. le1.— Hemioxyhexaster. (X 240.) FIG. le2. — Monoxyhexaster. (X _'4n.) FIG. I/.— Holodiscohexaster. (x 24(i.) FIG. I/1.— The same (part), (x 700.) FIG. Iff. — Microdiscokexaster. (Optic, sect.) ( x 700.) FIG. 2a-g. — Rossella antarctica Carter. Spicules of Specimen A. (Page 6.) FIG. 2a. — Parenchymal regular hexactin. (x 160.) FIG. 2b. — Autodermal pentactin. (x 160.) FIG. 2ft1. — Autodermal hexactin. (x 100.) FIG. 262. — Autodermal stauractin. ( x 160.) FIG. 2c. — Autogastral hexactin. (x 160.) FIG. 2d, 3d1.— Holoxyhexasters. (2tfl in optic, sect.) (x 160.) FlG. 2d3. — Hemioxyhexaster. (x 160.) FIG. 2d3. — Monoxyhexaster. (x 160.) FIG. 2d*. — Central part of 2d3, showing termination of axial canals. ( X 700.) FIG. 2e. — Hemidiscohexaster (modified), (x 700.) FlG. 2/.— Calycocome. (Optic, sect.) ( X 700.) FIG. 2//. — Portion of another calycocome with shorter smooth shaft and divergent rays, (x 700.) FIG. 2h. — Microdiscohexaster. (Optic, sect.) ( x 700.) FIG. 3a-k. — -Rossella antarctica. Spicules of Specimen C, only 3h being from Specimen B. (Page 8.) FIG. 3a, Sal. — Oxypentactin basalia. ( X 50.) FIG. 3i. — Autodermal pentactin. (x 160.) FIG. 3e. — Autogastral hexactin. ( X 160.) FIG. Sc1. — Autogastral pentactin, a kind only found in Specimen C. (x 160.) FIG. 3d.— Holoxyhexaster. (Optic, sect.) ( x 240.) FIG. 3d1, 3d2. — Hemioxyhexasters. ( x 240.) FIG. 3d3, 3d*. — Monoxyhexasters. ( x 240.) FIG. 3d6. — Stauractin -like monoxyhexaster. ( x 240.) FIG. 3d6. — Three spheroidal reduced oxyhexasters. (x 240.) FIG. 3e. — Seven discohexasters, showing variation in form. ( X 240.) FIG. 3«l. — Hemidiscohexaster. ( x 700.) FlG. 3f. — Calycocome. (Optic, sect.) ( x 240.) FlG. 3/1.— The same (a part), (x 70<».) FlG. 3g. — Part of another calycocome. ( X 700.) FIG. 3h. — Abnormal calycocome, from Specimen B. ( x 700.) FIG. 3Jc. — Microdiscohexaster. (Optic, sect.) ( x 700.) FIG. 31. — Portion of a variety of microdiscohexaster. ( X 700.) . > . • :' • • , PLATE V. FIG. \a-rn. — Rossdla pulai/rosa. Spicules. (Page 11.) FIG. la. — Parenchymal hexacfcin. ( X 50.) FIG. 11. — Parenchymal hexactin. (x 50.) FIG. If. — Autodermal pentactin. (x 160). FIG. Id, Id1, Id2. — Hypodermal oxypentactins. ( X 50.) FIG. 1«. — Autogastral hexactin. (x 160.) FIG. If, I/1.— Hemioxyhexasters. (x 160.) FIG. I/2, I/3.— Monoxyhexasters. (x 160.) FIG. If*. — Small monoxyhexaster. (x 160.) FIG. \g. — Calycocome. (Optic, sect.) ( x 240.) FIG. Iff1. — The same, (x 700.) Fir;.]//. — Small calycocome, without disks, (x 240.) FIG. Ik. — Holodiscohexaster. (x 240.) Fin. 11. — Monodiscohexaster. (x 240.) FIG. 1m.— Mierodiscohexaster. (Optic, sect.) ( x 700.) FIG. 2«-»«. — Anaulosoma srhulzii. Spicules. (Page 22.) KH;. 2«. — Parenchymal hexactin. (x 50.) FIG. 26. — Parenchymal pentactin. ( x 50.) FIG. ~2e. — Parenchymal stauractin. ( x 50.) FIG. 2d. — Parenchymal tauactin. ( X 5u.) FIG. -2e. — Autodermal pentactin. (x 1G<>.) FIG. 2/-2/4. — Modified (Autogastral ?) hexactins, and pentactin, all from Specimen C. ( x 100.) Fifi. :.'//, -'//', 2#2, -2(j3. — Holo-, Eemi-, and Mon-oxyhexasters. (The small " 2 " of 2g'2 is not visible on the plate.) ( X 1 60.) FIG. -2h.— Calycocome. (Optic, sect.) ( x 240.) FIG. 2A1.— Part of same. ( x 700.) FIG. 2/c. — Hemidiscohexaster. (x 240.) FIG. 2k1.— Part of the same. ( x 700.) FIG. 21. — < 'urious discohcxaster, with three orders of rays. ( X 700.) :'»(. -Microdiacohexaster. (Optic, sect.) (x7, t1.— Hypoderiiuil oxypentactins. (x 50.) FIG. lc.— Antogastral hexaetin. (x 160.) PIG. Id. — Holoxyhexaster. (x 24". ) FK;. I*/1. Ik'mioxyhexaster. (x iln.i FIG. If/2.— Monoxyhexaster. (x _'4iu FIG. If.— I'alycocome. (Optic, sect.) (.x ir.n. FIG. I/.— Holodisruhrxastcr. (Optic, sect.) ( x 240.) Fin. I/'1.— The same, one secondary ray. (x 700.) Fin. I//. .M icrodiscohexaster. (Optic, sect.) (xTmi.) PlG. i'-i'/r.- - Anhi, -ustn'Ui/ jiiloxii. (Page 1C>.) FIG. 2.— Gastral membrane, (x in.) FIG. L'I/. - Baaalial oxypentactin. (x .r>M.) Fn;. •_'//. -Autodermal pentactin. (X Hi11.) FIG. -2c. — Hypodernial pentacfcin. (x 50.) FIG. -2(1.— Holoxyhexaster. (Optic, sect.) (x 24.) FIG. 2d'.— Dwarf holoxyhexaster. (x 7i"M FIG. -2e— Calycocome. (Optic, sect.) (xi4o.j Fii.. iv1.— Portion of -V. (x Tun.) Kn.. i'/. Portion of calycocome from another specimen. ( x Tun. < l-'n:. ^i>.i FIG. 2d. — Autogastral hexactin. ( x 160.) FIG. LV. (imiihiocome. (Optic, sect.) (x.'4o. FIG. -(e1. -A part of same, (x 700.) FIG. -if. Strobilocoine. (Optic, sect.) (xi'4d.i FlG. 2/'1. A part of same. ( X 700.) FIG. •>ptic. sect.) (X i'40.) FIG. -2if. The same, (x 700.) MARINE I.-PH^EOPH¥GEJE AND FLOKIDE.E. By ANTONY **< //////nni. We erroneously recorded (Journal of Botany, Inc. cif.) L. i/riiiti//f"//ii as having been collected in the South Orkneys by the Scottish Expedition. Though we found the two plants so much alike in external habit, we have been compelled, after a further examination of their minute structure, to separate them specifically. The ' Scotia ' plant will be found below, described under the name L. siiiiii/itiix. The occurrence of two such large new species of alga: is a rather startling indication of how much may yet remain to be investigated in the South Polar marine llora. Mil.. III. '_' I. 2 ANTONY GEPP AND ETHEL S. GEPP. A small plant of Zonaria was found, which is too young to identify ; but it is interesting as the first record of this genus from the South Polar regions. l^-xiitifirxtin /Kirri'i/iinii (/>. •iiii'Jin of the Flora Antarctica) appears to have been abundant, and a specimen of over six feet in length has been brought home in the collection. Pkyllophora antarctica is the Antarctic congener of the northern species P. interrupts. Spongoclonium orlhodadum is a new species, allied to S. liirtum ( Callitliamnion hirtum of the Flora Antarctica). The conditions of life that control the algal flora at both poles are peculiar, and are not easily realised by those who have never visited the polar regions. The two totally distinct seasons — on the one hand, the prolonged winter night, together with the impenetrable crust of ice that effectually cuts off the sea from contact with the gases of the atmosphere sometimes for years, the increasing salinity of the water, clue to the rejection of salt during the formation of the deep layers of ice, the equable, low temperature of the denser, deeper waters below the ice ; on the other hand, the long summer day, accompanied by the breaking of the ice and melting of the ice and snow, the layer of fresher water on the surface, which slowly mingles with the sea-water below, the renewed absorption of atmospheric gases, the assimilation of carbonic acid excreted by the animals living there— these and other factors must profoundly influence and modify algal life and development ; and data concerning the effect of these conditions upon algae have yet to be accumulated. A critical comparison of the marine floras of the two Polar regions should bring out points of great interest ; and a fair field in this respect lies open to that expedition which is the last to publish the report of its collection of marine algae. Any attempt to draw up such a comparison now would necessarily be premature and incomplete. We await with interest the publication of the results of the other expeditions, in the hope that they may yield a more complete representation of the algal flora peculiar to the Antarctic region, and that incidentally they may throw light upon those points which we are compelled to leave in obscurity. PH/EOPHYCEyE. 1. ZONARIA sp. ( >fl' Cape Wadsworth, Couhnan Island. A small, immature plant, 2 cm. high, the thallus of which is still monostromatic throughout. Though unable to name the species, we think it worth while to include the plant in our list, as the genus has not yet been recorded from the far South. Zoi/nrni. is lucre used in its old and wide sense, as the specimen is too fragmentary to admit of further classification. .MAI; INK AUI.E. 3 2. LESSONIA GRANDIKOLIA. (Plates I. and II , figs. 5-9.) Lessonia grandifolia, Gcpp, Journal <>r lintauy, I:N>.">, p. 105. Callus radicalis dense ct irregulariter ramosus, coriaceus. Stipes valde com- pressus, marginibus obtusis, his vel ter vel quater dichotomus, subtcr (jun]ii(|uc dichotomiam complanate expansus ; rami sectione transversali plano-convexi ancipiles marginibus acutis, laxe torti. Stipes totus e callo usque ad laminas 30-120 cm. Lamina lanceolato-lineares-longissimae (1-8 met.), latee (8-45 cm.), marginibus grossc undulatis integerrimis, apice deleto, fissiles, in statu sieco coriacejc sed fragiles. Stipitis substantia lacunis annulisque carens. Lamina; substantia coriacea e stratis tribus composita ; cellulis corticalibus minutis fuscis congestis in series verticales breves dispositis ; subcorticalibus rotundatis 1-2 — seriatis i[iiam corticalibus magnitudine duplo majoribus ; hyphis medullaribus hyalinis extrorsum dense introrsum laxe iuvii-em juxtapositis flexuosis tubulos multos subinfundibuliformes vagina e cellulis parvulis composita vestitos circumstantibus. Zoosporangia ignota. Figs.' 1-9. Cape Adarc (Jan. 9, 1902), hauled up with anchor from 18 fathoms; Coulman Island, off Cape Wadsworth, 18 fathoms. In our previous account of this species (Journal of Botany, !.<:) we quoted specimens gathered both by the Scottish and the British Expeditions, and from the order in which they were cited it would naturally be inferred that the type described was the ' Scotia ' plant. We wish to state that the type was and is the ' Discovery ' plant, and that the diagnosis was founded upon it alone, the ' Scotia ' material being too fragmentary to furnish data for a complete description. Though at the time we regarded the ' Scotia ' fragments as belonging to L. //fi>fi the stem is subsidiary to the laminae, and the species is distinguished from all the rest of the genus by the great size of its unsplit laminae; the largest laniinaj previously recorded for any of the species were 60-90 cm. in length, and occurred in /,. fuxct '*<•< //*, Bory (Hooker, Flora Antarctica, I. 1847, p. 458). In our specimens of L. grandifolia the. largest lamina is 5'7 m. when drv, and, when tirst taken out of the loi-iiialin solution in which it was preserved, measured 7':'. m. in leiigih by 15 cm. in width. Another lamina measured I ' 5 m. by :',5 mi. wide when moist before "desiccation. Not f the mature fronds are complete at the apex, but we are unable to say whether or not this means thai the previous year's 2 L 2 4 ANTONY GEPP AND ETHEL M. GEPP. growth has died off above. These lamina? are simple, with undulate margins, and in this respect resemble somewhat those of Lamiimria saccharina ; but are of course far larger, and arise from a branched stem (figs, la and ib). The main stem is attached to the substratum by a dense ramified mass of leathery holdfasts, and is very short (15-22 cm. long), much compressed (5 cm. wide by about 1 • 5 cm. thick), in transverse section concavo-convex with rounded margins (fig. 3a, diagrammatic). It is divided above dichotomously into two branches which are much compressed, two-edged, laxly twisted, simple or 2-3 times dichotomously branched, and much flattened and expanded below each dichotomy. These branches vary in length from 15-105 cm., the younger branches being the longest ; they gradually taper upwards, and before expanding gradually or quickly into the great flat fronds, are reduced to a width of l'5-2'5 cm. when moist, and 0'3-0'T cm. when dried. At this thinnest point they tend to decay most readily when being dried. The branching of L. grandifolia is dichotomous, and we can find no indication in either the mature or very young specimens that the dichotomies are the result of a splitting of the developed frond such as is characteristic of some of the other species of Lessonia. Further, in some very young plants (fig. 2) of L. grandifolia, which we found growing on Desmarestia harveyana, it is interesting to note that though but 1-2 inches long, they are already as much branched as the huge inature plants ; and this shows that the dichotomous branching occurs very early in the life-history of the plant, and is not a feature of subsequent development. The structure of the mature lamina, as seen in transverse section (fig. 5a), consists, like that of the stem and branches, of three strata. Externally is a cortex of small brown cells, placed in short vertical rows, and crowded ; beneath it is a subcortical stratum of about 2 rows of rotundate cells twice as large as the cortical cells, and containing a coloured globose mass of contracted protoplasm. This subcortical stratum passes almost at once into the closely packed, short-celled, irregularly flexuose, longi- tudinal hyphse which form the external limit of the medulla and which in transverse section form a band of tissue apparently composed of 8-10 rows of subrotuudate cells of varying size ; the interior of the medulla is composed of hyaline hyphse mostly running longitudinally, laxly juxtaposed in the gelatinoid matrix and separated from one another by 1-2 times their diameter. Embedded in this medulla and dotted along an irregular median line, which stretches across the lamina from edge to edge, are a number of trumpet-hyphse, rather resembling those described by Grabeudorfer (Bot. Zeit., vol. XLIIL, 1885, p. 645, tab. VI., fig. 11) for L. ov). These trumpet- hyphae run in a sinuous course both longitudinally and transversely, and are found even in the youngest plants. They serve, perhaps, as mucilage tubes. When seen in longitudinal section (fig. 7), they exhibit on their walls very fine and faint transverse striatioiis (confer fig. 9). We have failed to find any such trumpet-hyphsB at all in any other species of Lessoniit (except L. simulant; see p. 6), e.g. L. fuscescens, L. MAUlNti AUUO. 5 i'iix, and L. li/fnmf!* ; and even in L. nv/itu the " Trichter " (as Grabendorfer calls them) differ iu being more inflated at their funnel-shaped ends and quite destitute of a .special sheath. In the very young lamina (.] in. long), the structure is much simplified (fig. G). The cortical cells are crowded, and obscured by coloured granules and form a mono- stromatic layer, beneath which is the subcortical stratum of about 2 rows of large cells, round in transverse section, or sometimes twice as long as broad in longitudinal section of lamina (fig. 8). In the middle lies the medulla, consisting of some three or more rows of longitudinal or transverse hyaline hyphas ; among them are very few trumpet- hyphaj, each in its sheath. As to the structure of the stipes, it is in the main similar to that of the mature lamina, but the cortex is a little thicker and more deeply coloured, the medulla is far thicker and the sub-cortical layer much less distinct. In a transverse section there is a narrow, more opaque, median band stretching right across, along the widest diameter, distinctly visible to the naked eye (fig. 3b). This, under a low power of the microscope, is seen to contain dots and streaks (fig. 3c, and 4), which, under a higher power, are seen to be trumpet-hyphge in transverse and longitudinal section (fig. 9). The structure of the basal holdfasts is simple, the main tissue being composed of thin hyaline hyphse mainly longitudinal, most of them exhibiting a contracted globose mass of coloured protoplasm ; this tissue contains no enshcathed trumpet-hyphae and passes gradually through a cell-like subcortex to a submonostromatic cortex of small cells obscured by coloured granules. Neither stem nor lamina possess any lacuna) like those that characterise L. iiii/i'i'xri'iix and other species. L. i/nniiJifuliii resembles our L. xhnulnns in external habit, but differs in structure, as we show under that species. It also approaches L. laminarioides in habit, but differs from it in being 10-20 times as large, in having the steins flat and twisted, and the medullary hyphaj interspersed with the ensheathed trumpet-hypha) mentioned above. L. nn/fn, though, as we have said, possessing trumpet-hyphse somewhat like those of our plant, is otherwise very different, having small oval lamina) less than 20 cm. long, and a stem which, according to Grabendorfer (<>j>. <•!/., p. G43), may attain a length of several metres and a thickness of about 10 cm. •ft1 3. LESSONIA SIMULANS. (Plate II., fig. Ifi.) /.. si/ii/ilii/ix us elongatis angustis strietis 9-10 seriatis tubulos perpaucos subinfundibuliformes vagina e cellulis parvulis eomposita vestitos foventibus. Caetera desunt (fig. 10). South Orkneys, Scotia Bay, near surface; April, 1904, leg. R. N. Rudmose Brown. A section of the lamina of this plant was figured in the Journal of Botany (loc. elf.) as representing that of L. l!, pp. IDS, 102. Frondes plures (8-10) e ealln miuuto ortse simplices oblongae vel lato-cuneatse planse membranacae, 10-15 cm. longae (apice destructo), 3-8 cm. latae, c. 230/i %'OL. III. 2 M 10 ANTONY GEPP AND ETHEL S. GEPP. crassge, inferne in stipitem plus minusve sensim augustatum, 1-3 cm. longum attenuatse, stratis duobus contextse cellulis interioribus rotundato-angulatis niagnis o o 2-3 seriatis pachydermis (frondis sterilis majoribus maxime leptodermis collabentibus submonostromaticis) ; cellulis corticalibus filamenta ramosa verticalia efficientibus, tetrasporangia magna cruciatim divisa foventibus (frondis sterilis majoribus mono- stromaticis). Oft* Cape Wadsworth, Coulmau Island. Geogr. Distr. — South Orkneys. This species is represented in the ' Discovery ' collections by one specimen only, a single thin dried frond 22 ' 5 cm. long by about 1 • 5 cm. broad at its widest part. Blunt and incomplete at apex, it tapers very gradually down to its attenuated stalk- like base. This frond is quite sterile, and owing to the collapsed condition of its cells as the result of drying, was not in itself sufficient for determination, for we altogether failed to make the cells swell out again. Fortunately we found in the ' Scotia ' collection from the South Orkney Islands two specimens, which clearly belong to the same species, and being preserved in spirit, and uncrushed, revealed to us the interior tissue in its natural condition. These ' Scotia ' specimens were also sterile, and we described them under the name Leptosarca simplex (loc. cit.). Subsequently we received a more complete plant, also from the S. Orkneys, which with a few other algae had been overlooked in the ' Scotia,' until she was cleared out previous to being sold. This plant bore ten fronds, some sterile, others tetrasporiferous. The two kinds of frond exhibited differences of structure, the sterile being characterised by an internal layer of large, extremely thin-walled cells, bounded by a monostromatic cortex, as described for Leptosarca (loc. cit.}, while the sporiferous fronds with their large cruciate tetraspores, thicker-walled internal cells and pluristromatic cortex compelled us to transfer this species to Gracilaria, of which genus it should perhaps form a new section. 9. GRACILARIA UUMONTIOIDES. (Plates III. and IV., figs. 17-20.) Halosaccion dtimontwides Harv. ex Dickie, Journ. Linn. Soc. IX. (1867), p. 239 (nomen tantnin). Li'/i/osarca dumontioides nob. in Journal of Botany, April, 1905, p. 108 (nomen taiitum). Frons (vetusta incompleta) liuearis, 6 ' 5 longa, 4 mm. lata, complanata, membra- nacea, prolificationes plurimas, intervallis irregularibus circ. 4 mm. latis invicem scparatas, maxime e marginibus ambobus emittens ; prolificatioues 4-15 cm. longte infra medium valde attenuate tune sensim sursum expanses vel anguste lineares 4mm. laho simplices vel cuneato-lineares latiores apicem versus dichotomy, ramis valde divergentibus. Color rosaceo-ruber. Cystocarpia et tetrasporangia ignota. Northumberland Sound, 76° N. lat., July 1853, leg. D. Lyall (fig. 20); Capo A dare, 72° S. lat., February 24, 1904 (fig. 17). The only Antarctic specimen (fig. 17) which we have seen consists of a scrap of an old frond, destitute of base and apex, encrusted by a zoophyte, and bearing laterally MARINE ALGJE. II from its edges about fifty proliferations. The whole plant is quite sterile, of very thin texture, and consists of an internal tissue enclosed in a cortex which is moiio- stromatic except at the margin. The structure, however, owing to the crushed condition of its interior cells, affords but little clue to the systematic position of the plant, and all our efforts to make the internal tissue swell out to its original dimensions were in vain. We were therefore unable to figure the structure except near the much- thickened margin of the proliferating scrap of old frond mentioned above (fig. 18). The cells of the monostromatic cortex are large (fig. 19). In habit it resembles Dumontia, but has not the hollow thallus and filamentous cell -structure of that genus. Our plant has a solid thallus, and for that reason we should not have searched for it under Ilalosaccion, but strangely enough we find the Cape Adare plant to be apparently identical with //. diiHinnt'm'nlcx Harv., an undescribed species from the far North. The habit, the thin texture, the mono- stromatic layer of rather large coloured cortical cells, and the permanently collapsed internal tissue are the same in both. The proliferations in Harvey's plant are linear and very long (fig. 20) ; in the Cape Adare plant they are half as long, and are cuneato-linear and tending to be forked at the apex. Dickie (Journ. Linn. Soc. IX. [1867], p. 239) stated that II. dumontioides was first described by Prof. Harvey from specimens found by Dr. Lyall in Lat. 76° N. We failed, however, to find any published description, and applied to Dr. E. Perceval Wright, Keeper of Harvey's herbarium, Trinity College, Dublin, for information. He kindly replied : — " I think that a description of Ilalosaccion dumontioides has never appeared. Dr. Lyall's specimens were collected in July, 1853. Harvey was on his Australian tour, 1853-56, and in 1857 was busy with his P/iycnlni/in Australica (1858-1863). All our sheets with Lyall's specimens are marked in pencil with the name and ' Harv. MS.' Now when Harvey published a name, he mostly wrote the name in ink on the sheet. On one of our sheets he has written, still in pencil, ' Can this be a var. of //. r/nncn- taceum ? ' It is strange that J. G. Agardh did not write to me for a specimen in 1876." — that is, before publishing his Epicrisis. Harvey, having only dried material to work upon, and being therefore unable to determine the character of the internal tissue, was in doubt as to the affinity of the plant, and placed it in Ilalosaccion near H. ramentaceum. There we should have been compelled to leave it, had we not found a similar crushed tissue and monostromatic cortex in another species, Gracilaria simplex, of which we had received not only dried specimens, but also spirit material, and to which we regard our plant as closely allied. However, none of the specimens of either species have cystocarps, and their systematic position may have to be reconsidered later.* Dickie (lui: ''/>.) records plants collected in Cumberland Sound (HO0 N. lat.) by * Since these lines were sent to press we have seen some very fine Antarctic specimens, collected by Dr. C. Skottsbortf during the Swedish South Polar Expedition, which lead us to believe that our Antarctic plant is not fully grown, and is not conspecific with Harvey's plant of G. dumontioides. Dr. Skottsbcrg will deal with the question in his own report. 2 M 2 12 AXTONY GEPP AND ETHEL S. GEPP. James Taylor. These are in the British Museum, and are small (about 10 cm. long). They appear to be the same species, but are stouter in texture. Lyall's specimens, of which there are fine examples in the British Museum and in the Kew herbarium, measure 30-40 cm. and bear the MS. note — " a xiiuill specimen." They were collected in Northumberland Sound, Queen's Channel (76° 5' N. lat, 97° W. long.) on July 14, 1853, during Belcher's Expedition. The distribution of the species is notable. It occurs only in the extreme north (76° N. lat.) and in the extreme south (72° S. lat.). 10. PLOCAMIUM COCCINEUM. Plocamium coccineum Lyngb., Tent. Hydroph. Danic. 1819, p. 3D, t. !» Off Cape Wadsworth, Coulman Island, with cystocarps. Geogr. Distr.— Mediterranean, N. and S. Atlantic, N. Pacific, Cape of Good Hope, Australia, Tasmania. 11. DELESSERIA QUERCIFOLIA. Delesseria qt/ercifolia Bory, Voyage Coquille, 1828, p. 18G, t. 18, fig. 1. Off Cape Wadsworth, Coulman Island. Geogr. Distr. — North Pacific, Falklands, Cape Horn, Kcrguclen. Sterile and somewhat battered specimens. 12. PHYLLOPHORA ANTARCTICA. (Plate IV., figs. 21 and 22.) Phijllophora antardica Gepp, Journal of Botany, 11105, p. 10',). Off Cape Wadsworth, Coulman Island. Frons e stipite brevi mox in laniinani membranaceam ligulatam ssepius opposito- sinuatam simplicem vel dichotomam expansa, ramis approximatis siuu angustissimo et ad apicein et secundum margines prolificantibus ; cystocarpiis marginalibus pedicellatis ; tetrasporangia ignota (figs. 21, 22). This species is represented in the collection by several specimens, both fertile and sterile, mostly fragmentary, and exhibiting considerable variability of external form (fig. 2lb). The longest specimen (fig. 21a), though incomplete, is about 17 cm. high and about 1 cm. broad, with a single dichotomy. The smallest complete specimen is 5 cm. long and unbranched. The lamina is membranaceous and ligulate, slightly undulate at the margin, with shallow constrictions at intervals of about 2 cm. ; where a dichotomy occurs the branches are very close together, almost touching. The pro- liferations along the margin are often numerous, and are usually quite small, whilst those at the apex are sometimes as large as the primary frond ; and where three or four occur together, they give the plant a digitate appearance. In transverse section the thallus is seen to be composed of two strata. Within are two to three rows of lax, empty, polygonal, very thick-walled medullary cells, surrounded by a cortex of two to three rows of minute flattened coloured cells (fig. 22). The cystocarps are marginal, MARINE ALG/E. I '•'< cither sessile or very shortly pedicellate, ovoid and bluntly rostrate. The pericarp is composed of six or more rows of cells in vertical series. Its nearest ally is P. interrupta, which it somewhat resembles in external form ; but it differs from that species in having simpler and more longly dichotomous branching (being very rarely or never palmate), and the apices of the branches ligulate and not reniform or rotundate. The thallus is not moniliform or torulose, but merely opposito-sinuate. P. interrupta is more shortly dichotomous, and often has a triangular expansion below its dichotomy, and palmate branching. The constrictions, too, are often reduced to almost stalk-like thinness, which is not the case in P. nntnrcli<-«. P. interrupta is an Arctic species, and P. antarctica appears to be its Antarctic couo-ener. Possibly they are antipodal polar descendants from a common ancestor. P. Brodicei J. Ag. differs in its long stipes cuneately expanded into a more or less palmate frond, and is apparently the Arctic congener of the Antarctic P. cuneifolia, which has shorter stipes, broader less-lobed frond, and broader shorter lobes with shallower sinus. 13. SPONGOCLONIUM ORTHOCLADUM. (Plate IV., figs. 23-25.) Frons 8 cm. alta dense fruticulosa axi central! crecto tereti rhizoidibus hand corticato ramulis ascendentibus velato, quoquoversum ramoso, ramis cauli similibus ramulis ultimis longis erecto-patentibus simplicibus strictis subulatis, articulis diametro sesquilongioribus, articulo basal! mine nudo mine procarpium intra ramcllorum minutorum fasciculum emittcnte. Tetrasporangia ignota. Cape Adare, January 9, 1902. This is a densely bushy plant (fig. 23) of moderate size, about 8 cm. high without the basal attachment and without tetraspores, but bearing young procarpia with tricho- gyues (figs- 25a, 25b), and so thickly infested with diatoms that it is difficult to obtain a clear view of its ramification. S. orthocladum is remarkable for its long straight subulate ultimate branchlets (fig. 24), and differs in this respect from all the fruticulose Callithamnioid species which we have seen. Its nearest ally is found in certain states of S. hirtum \_C(dlithamnii>n hirtum Hook. f. and Harv. in Flora Antarctica, II. (1847), pi. Ixxviii., figs. 3 and 4], a plant recorded from the Auckland Islands and Ki-\v Zealand. The typical plant, it is true, differs inter all it in having ultimate pinnse consisting of a flexuose rachis bearing sub-distichous incurved obtuse ramelli. There is, however, in the British Museum a specimen from Cook's Straits, New Zealand, collected by David Lyall and named by Harvey, which, though normal in most respects, yet has a few branches which break up into long, straight, subulate ramelli like those of our plant. 14 ANTONY GEl'P AND ETHEL S. GEPP. EXPLANATION OF PLATES I— IV. PLATE I. Lfssonia yra/i/lifoUa nob. Figs, la, Ib. Mature fronds, showing flattened stipes clichotoraously branched and usually twisted, bearing long, simple, flat fronds with undulate margins and broken apex ; -,V natural size. Fig. 2. Three very young plants attached to a branch of Desmarestia harveyana, and exhibiting even at this early stage almost as much branching as is found in a mature plant ; natural size. Fig. ?,a. Transverse section (diagrammatic, and showing no cell-structure) of stipes at base of fig. la, showing concavo-convex form and rounded-obtuse margins ; natural size. Fig. Zl). Transverse section of stipes, being the top of the cut branch on the left of fig. Ib, and showing two acute margins and a long, light-coloured intra-medullary band ; natural size. Fig. 3e. Portion of same (about two-thirds of its width), showing that the intra-medullary band is composed of the cross-sections of scattered trumpet-hyphffi ; the bulk of the section consists of medulla, limited on the outside by the indistinct subcortex and the pigmented cortical stratum, (x 10.) Fig. 4. The same in longitudinal section ; the medulla here is also indicated by the trumpet-hyphre, which appear as longitudinal streaks, (x 10.) PLATE II. Lessonia grandifolia (continued). Fig. 5n. Transverse section of mature lamina, representing one- half only of its thickness, and showing on the left the short, vertical rows of pigmented cortical cells ; beneath this is the subcortical stratum of about 2 rows of rotundate cells, which are twice as large as the cortical cells and pass into the closely packed hyphse which form the outermost portion of the medulla and appear here as round cells, but are shown to be hyphae in longitudinal section (compare fig. 7) ; these hyaline hyphtc become more and more separated towards the middle of the medulla, and run in various directions through the gelatinoid matrix, and among them are shown a few ensheathed trumpet- hyphrc. (x 110.) Fig. ob. Small portion of similar section, showing four truinpct-hyphai with their sheaths of small cells and a few of the ordinary hyaline hyphas of the medulla, (x 450.) Fig. G. Transverse section through a very young lamina (as in fig. 2), showing a nionostroniatic cortex of granular coloured cells, a subcortical layer of 1-2 rows of large clear cells, and a medulla composed of a few lax byphffi and one ensheathed trumpet-hypha. (x 450.) Fig. 7. Longitudinal section of mature lamina representing half the thickness of the frond, and showing (as in fig. 5«) the short vertical rows of pigmented cortical cells ; the subcortex of 1-2 rows of rotundate cells twice as large as the cortical cells ; and the medullary hyphte densely packed on the outer side and becoming gradually more laxly arranged towards the interior, where, interspersed among them, are portions of three fcrumpet-hyphse in longitudinal and one in transverse section. (X 110.) Fig. 8. Longitudinal section of very young frond, showing the three strata already described for fig. C. ( X 340.) Fig. 9. Portion of medulla of stipes in longitudinal section, showing a trumpet-hypha with its sheath of small cells and its wall densely marked with transverse stride ; the cell-contents have contracted into a narrow strand along the axis of the cell. ( x 450.) Lrxfiniiiu, sinntlans sp. nov. Fig. 10. Outer part of a longitudinal section of stipes, representing the external part of the medulla, which is composed of densely packed straight hyphte ; these latter externally pass gradually into a pluristromatic subcortex of large round and transversely oblong cells which, running radially outwards towards the periphery, subdivide more and more, forming a cortex composed of short vertical rows of small quadrate cells, (x 110.) PLATE III. firxmiirt'xlifi liiiri'i'ijniiii nob. Fig. 11. Small portion of a largo plant, stowing that the ramification is always opposite ; natural size. Fig. 12. Apex of an ultimate branchM in surface view, showing that the cortex is continued to the very apex of the axial filament, (x 110.) Fig. 13«. Transverse section of a mature stem, showing its compressed form ; in the centre is the ensheathed primary axial filament and, MARINE ALGJE. 15 to the right and left, some fifteen secondary similar filaments each in its sheath of small cells, (x 25.) Fig. ISb. Part of the same, showing an ensheathed secondary filament apparently containing tyloses ; the large cavity on the left is merely an ordinary cell of the thallus. (x 4;V>.) Fig. 14«. Longitudinal section of mature stem, showing the primary axial filament with its branches (secondary filaments) and their anastomoses; all these filaments are distantly articulated, (x 4.) Fig. HI. Small portion of longitudinal section of stem, showing a secondary filament faintly indicated within its sheath of small cells, (x 340.) Fig. 15. Transverse section of an ultimate raniulus showing the primary axial filament in the centre, (x 110.) Desmarestia viridis Lain. var. distans, Hook, and Harv. Fig. 1(5. Transverse section of stem, showing a denser medullary tissue in which the primary axial filament lias become obliterated, (x 25.) Graciliti-iii. dumontiouks nob. Fig. 17. Antarctic specimen consisting of numerous cuneato-linear proliferations arising from a fragment of an old frond ; natural size. PLATE IV. G-rttciliiria dumontioidi'S — (continued). Fig. 18. Transverse section of the above-mentioned fragment of old frond near its margin, where the cortex becomes thicker and polystromatic ; the internal tissue consists of large cells permanently flattened in drying the plant, (x 400.) Fig. 111. Monostrornatic cortex in surface view, (x 650.) Fig. 20. Arctic plant named by Harvey Halosaccion dumontioides, collected by Dr. Lyall in lat. 7(T N., and preserved in the British Museum ; its proliferations are very long and simply linear ; natural size. Phyllopliora aiitarrtica nob. Fig. 21«. Plant bearing marginal cystocarps ; natural size. Fig. 21&. Sterile plant bearing large and small proliferations ; natural size. Fig. 22. Longitudinal section of cystocarpic branch, containing a compound cystocarpic nucleus, (x 80.) Spongoclonium orthodailum sp. nov. Fig. 23. Part of plant ; natural size. Fig. 24. Rather diagrammatic representation of apical part of a branch, showing the long, straight, subulate ramelli. (X 35.) Figs. 25«, 256. Young procarpia with trichogyne. Antarctic (Discovery) Exp. P Highley, London- J^ I : -V. 1 Discovery.) Exp !4t- Antarctic (Discovery) Exp. Alga PL 3. P. Highley, London. Antarctic (Discovery) Exp. Alga&*P1.4. P. Highley, London. MAEINE ALGJ5. II.-CORALLINACE^. By M. FOSLIE. LITHOTHAMNION COULMANICUM. the Natural History collections made in the Antarctic regions by the ' Discovery ' Expedition are some specimens of a calcareous alga, which has been kindly sent me for determination. They proved to represent a species new to science belonging to the genus LithotJiamnion, which I shall now describe. The species has been shortly mentioned in " Det Kgl. norske Videnskabers Selskabs Aarsberetning " for 1904, p. 16 (Trondhjem, 1905), under the name of LITHOTHAMNION COULMANICUM FOSLIE. The plant forms incrustations on pebbles. The crust is closely adherent to the .substratum when young, but when older it is here and there rather easily detached, LITHOTHAMNION COULMANICUM FOSL. NAT. SIZE. particularly when attacked by animals or when covering extraneous objects. It is thin, in the specimens brought home the thickness not exceeding 800/z, frequently being less, or about 300/x. The shape of young crusts is frequently more or less irregular, but now and then almost circular, and so also when older, but then the plant sometimes fully surrounds the substratum. It is sometimes indistinct concentric zonate, and the edge is crenulate or irregular. Several crusts are often found on the same substratum. They may run into each other, in some cases not showing any visible mark where the joining takes place, in others here and there forming slightly elevated ridges. The nature of the surface is determined by that of the substratum. If this is smooth the crust is also smooth, and shines slightly when young. Older VOL. III. - N 2 II. FOSUK. crusts often become a little uneven and finely rugged on the surface by growing over small extraneous objects. Besides, in most of the specimens collected the surface of the crust is somewhat rubbed, probably owing to the friction of the water by a rather strong current. A similar appearance is often to be seen in northern Lithotkamnia, particularly in sounds where the tides run strongly. In a vertical section of the crust the basal hypothallic layer is distinctly, but not strongly, developed, and the convergence of the lower anticlines of this layer towards the substratum is very feeble or wanting. The cells are 12-18/t long and 4-7/n broad. In the perithallic layer there is no stratification to be seen. The cells are here partly squarish, often with rounded corners, 5-8/A in diameter, partly and more frequently vertically elongated, and 8-1 2/A long, with a breadth of G-8/x,. Here and there are to be seen cells with the longest diameter in the vertical direction, always, however, in very small numbers in proportion to the squarish or vertically elongated ones. The cell-walls are frequently rather thick. As regards the organs of reproduction, the cystocarpic conceptacles are somewhat crowded, subhemispheric-conical, but not quite superficial, as is frequently the case in this genus, 300-350 or up to 400ju. in diameter, when seen from the surface. They have been found only in one specimen, and most of them are in a state of decomposition. In a few other specimens conceptacles of sporangia occur. They are in some cases rather scattered here and there in the crust, in others somewhat crowded, convex, and but little prominent, often when older almost disc-shaped, 300-400/u in diameter seen from above. The roof is intersected with about thirty to forty muciferous canals, which are crowded in the central portions. The sporangia are two-parted, 90-1 20/A long and 40-50/A broad. These organs were ripe in the latter half of January. However, the greatest number of conceptacles observed were dissolved, leaving a shallow hole or a cup-shaped scar, which later on becomes effaced by new-formed tissue. Once I met with overgrown conceptacles in the thickest part of a crust, showing that these organs may become fully dissolved only in the thinner and rather young specimens. The present species stands nearest to Lithothainnion magellanicum, the latter, however, being a coarser plant with, as a rule, larger and more prominent conceptacles of sporangia and frequently larger cells. Besides, the sporangia are always four- parted (tetrasporic) in L. magellanicum. On the other hand, the species in question in some respects reminds one of the Arctic species Lithothamnion Iceve. Sterile specimens can on a superficial examination easily be confounded with Lithophyllum decipiens. This is the first species known from the Antarctic regions bearing two-parted (Itisporic) sporangia. Such were hitherto only known in some species of the genus in question from the Arctic regions. The plant was collected oft' Cape Wadsworth on Coulman Island, near South Victoria Land, about 73° 30' S., 170° W. Here it was picked up from a depth of 18 fins. It seems to have been pretty plentiful, as some sixteen pebbles with iin-nislutioiis of I ho species were collected. MUSCI. Par J. CARDOT. (2 Planches.) PRESQUE toutes les mousses autarctiques connues jusqu'ici provenaient tie 1'archipel ill- Graham et des iles voisines, c'est-a-dire de cette partie de I'Autarctide situee an sud dc 1'Amerique, et comprise entre le G06nie et le 65to)e paralleles. Les especes rapportrrs de la Terre Victoria par 1'expedition de la ' Discovery,' bien que peu nombreuses, presentent done beaucoup d'interet, non seulement parce qu'ellcs nous viennent d'um- region dont nous ne connaissions absolument rien jusqu'alors au point de vue botanique, inais aussi parce qu'elles sont actuellement les especes les plus australes connues, ayant etc re'coltees cutre 77° et 78° de latitude Sud. II est fort probable qu'elles constituent, avec quelqucs Lichens, les derniers et chrtifs representants de toute vegetation terrestre dans la direction du Pole austral. Si 1'on reflechit que, d'apres les observations thermometriques faites au port d'hiveruage de la 'Discovery,' par 77° 50' lat. S., de fe'vrier 1902 a fe'vrier 1904, la temperature moyenne des deux mois les plus chauds, de'cembre et Janvier, est de 3*80° C. an dcssoiis de zero ( = 24*95° F.) ; que le maximum observe, en decembre 1903, a ete de 5 '55° C. au dessus de zero (= 42 F.), mais que, meme pendant ces deux mois d'ete, k- thermo- metre est plusieurs fois descendu en dessous de— 10° 0., et qu'eu Janvier 1904, il a marque' — 15 ' 55° C. ( = 4 F.), on peut etre surpris qu'il soit encore possible a des vi'-gc'-taux d'une organisation aussi delicate et relativement aussi compliquee que les mousses de se developper et de vivre dans de semblables conditions climateriques. La plupart portent d'ailleurs les traces de 1'apre lutte qu'elles soutiennent pour 1'existence. Toutes forment des gazons extremement compacts, afin de pouvoir resister a la pressiou des epaisses couches de neige qui les recouvrent pendant les longs mois d'hiver. Le Bryum aryenteum, espeee cosmopolite, se presente ici sous un aspect tellement rabougri que les plus longues tiges que j'ai mesurees ne de'passaient pas uni- hauteur de 3 millimetres, et que les plus grandes feuilles atteignaienl seulement 0*35 niillim. Le Bri/nm . inconnexum Card., &Q detroit do (lerludie, mais elle s'en distingue par ses ga/oiis tres coliereiits el compacts, ses tiges plus greles, ses feuilles de forme variable, ordinairement agglomerees en totiiles au 6 J. CARDOT. sominrt drs tildes ct des rameaux, a bords moius longucment et moins reguliercment revolutes, souvent presque plans. Sur une section transversale, la nervure presente ordinairement un groupe de stenocystes en dessous dc 1'assise d'eurycystes ; mais les stereides font de'faut ; elles sont remplace'es par des cellules plus petites que les ele'ments epidermiques, mais a lumen cependant assez large et a parois peu e'paissies. Dans deux especes du detroit de Gerlachc, B. inconnexum Card, et B. Gerlackei Card., la nervure est e'galement depour- vue de vraies stereides, et ne presente que des substereides, et il est tres remarquable qu'une espece arctique re'cemment de'crite, le B. languidum Hag., de 1'ile Disco, sur la cote occidentale du Greenland, possede une nervure organise'e exacterncnt comme celle du B. algens* II est probable que cette alteration de la structure typique de la nervure dans le genre Bryum est due a 1'influence du climat polaire. Les echantillous de B. algens de Granite Harbour m'ont presente trois sortes de flours : les unes males, contenaut un grand nombre d'antheridies, entremelees de paraphyses tres nombreuses, plus lougues, hyalines, legerement atte'nuees au sommet ; les autres femelles, renfermant des archegones plus ou moins parfaits, entoures de paraphyses plus courtes qu'eux ; eufin, des fleurs renfermant a la fois des antheridies et d'autres organes mal developpes, mais qui paraissent etre des archegones imparfaits, plus ou moins atrophies ; 1'espece serait done polyoi'que. Ce caractere la rapprocherait du B. languidum Hag. , dont il vient d'etre question, et auquel elle ressemble aussi par la forme et le tissu des feuilles, mais qui s'en distingue d'ailleurs par ses gazous laches, peu cohe'rents, par ses feuilles distinctement marginees, et par sa nervure moins large (diam. GO-70 /*).— PL II. EXPLICATION DES PLANCHES. PLANCHE I. Fig. 1 a 11. Duli/modon i/elidus Card. — 1, plante, grandeur naturelle. 2, unetige x 3. 3, partie d'une section transversale de la tige X SCO. 4, 5, ('., 7, feuilles X 35. 8, tissu de la partie basilaire d'nne feuille X 360. 9, tissu de la partie moyeune d'uue feuille x 3GO. 10, tissu du sommet d'tnie feuille X :i(!0. 11, section transversale de la nervure x 3GO. Fig. 12 a 17. Ccratoilon purpureus Brid. forma. — 12, 13, 14, 15, 1C, 17, feuilles de formes diverses X35. PLANCHE II. r.ri/inii dl:/i;ix Card.— 1, 2, plantes, grandeur naturelle. 3, sommet d'une tige X 3. 4, 5, 0, 7, feuilles inlVrienres des innovations x 17. 8, it, 10, 11, 12, 13, 14, 15, feuilles moyennes et snpcrietires des innova- tions xl7. 10, 17, sommet dc deux feuilles X 43. 18, tissu de la partie basilaire d'une feuille X 184. 10, tissu de la partie moyenne d'une feuille X 184. 20, tissu de la pointe d'une feuille X 184. 21, section transversale dc la nervure X3CO. * Cfr. Hagen et Porsild, Mcddel. om Grocul., XXVI. p. 463, pi. XV. I..ISDIIN : I'KIXTKH II Y WILLIAM CLOWES AND S"NS, LIMITED, DUKE STREET, STAMFUKD STKEET, U.K., AND QKKAT WINDMILL STI1EET, W. Mosses Plate I. I -, ~1 g$g ^ - _ 1-^ — , ' ^ S!~ ^^^*> — ^ ' " 10 Antarctic (Discovery) Exp. ,rdot axinat.del., Wesb.Newma Fig.1-11. Didymodon gelidus Card. . Fig 12-17. Ceratodon purpureu Plate II. Antarctic (Discovery) Exp. J. Cardot adna-t.del.. We: Bryum algeris Card. " • . i I • . . • •• BM •/$• ' I • > I • .