XXIII. REPORT ON SOME SPECIES OF THE GENERA BUCCINUM, BUCCINOPSIS, AND FUSUS, DREDGED OFF THE SOUTH-WEST OF IRELAND. BY HENRY K. JORDAN, F. G. S. (COMMUNICATED BY DR. SCHARFF.) [Read MAY 23, 1892.] THE specimens submitted for the purpose of this Report were contained in six jars and bottles and in seven boxes. For facility of reference, the former will be lettered A to F, and the boxes numbered 1 to 7. Their contents were: Jar A. Fusus islandicus, Chemn.: one live example. Fusus gracilis, Da Costa: two dead examples. Buccinopsis dalei, J. Sowerby: two dead examples. Jar B. Fusus antiquus, Linn.: one specimen. Fusus jeffreysianus, Fischer: one specimen, dead. Fusus fenestratus, Turton: three specimens, dead. Buccinum humphreysianum: one live specimen in a tube, and Jar C. Fusus berniciensis, King: two dead examples. Buccinum humphreysianum, var.: one dead example. Fusus antiquus: one live and one dead. Jar D. Fusus gracilis: one specimen. Fusus jeffreysianus: one dead example. Jar E. Buccinum undatum, Linn. : one live and one dead specimen. Jar F. Fusus gracilis: one example. Fusus propinquus, Alder.: one dead specimen. Box 1. Marked "Warren Collection, loc. :?" Fusus gracilis: a series of five specimens. Fusus antiquus: three young examples mixed with above. Buccinum undatum, fry: in two tubes. Box 4. Fusus despectus, Linn. : a dead and fragmentary specimen. Box 5. Fusus jeffreysianus: in a tube, marked " F. propinquus (?)." Box 6. Fusus jeffreysianus: a series of live shells in bad condition. Box 7. Fusus propinquus, var.: one specimen. The specimens above mentioned will now be described in detail. Those in the jars have been retained in spirits, as desired, for the preservation of organisms adhering to some of them. GENUS, Buccinum, Linn. 1. B. undatum, Linn. It is remarkable that of this widely distributed and prolific species there are only two small examples, one live and one dead, and a few of the fry. These are of a form approaching the type and call for no special comment. 2. B. humphreysianum, Bennett. Of this much rarer species there are three live and one dead of the type, and one dead specimen of the following variety in Jar C: B. humphreysianum, var., ventricosum, Kiener. This is an interesting and remarkable form, and undoubtedly new to the British fauna. It is the B. ventricosum of Kiener, and occurs on the coast of Provence. According to the Marquis di Monterosato, Kiener's shell is the B. striatum, Phil., a Sicilian fossil. I have compared the specimen under notice with B. ventricosum from Provence. The two shells agree in size, contour, and texture; but the spiral striæ of the Provence shell, which are clearly visible to the naked eye on the upper and lower part of the whorls, disappear at the periphery; whereas on the Irish specimen the striæ are stronger and occur regularly over each convolution. The fineness, or coarseness, of striation is merely a question of degree, and in this respect some univalves vary greatly, as will be noticed when describing Fusus gracilis. B. ventricosum and B. humphreysianum have hitherto been regarded as distinct species, but Jeffreys in describing the latter species says:-" B. ventricosum of Kiener (from the coast of Provence) is closely allied to our shell" (British Conchology, vol. iv., p. 294). The specimen under notice clearly connects the two species; it is 2.1 inches in length, and 1.2 inch in breadth. GENUS, Buccinopsis, Jeffreys. Buccinopsis dalei, J. Sowerby. Of this rare species there are two dead examples in Jar A, the smaller specimen having a semi-fossilized appearance, and a dead example in Jar C. This species has recently been taken near St. Kilda, and is found around the Shetland Isles, and off Aberdeen, and the Yorkshire coast. GENUS, Fusus, Bruguiere. This generic appellation will be used in this Report in the broad sense in which it was employed in "British Conchology." Modern opinion probably leans to the view that the learned author of that work merged into this genus species which should be grouped in two or more genera. Until a new standard work upon the British Marine Molluscan Fauna appears, it will be wise to conform to Jeffreys' arrangement. 1. Fusus antiquus, Linn. This common species, which is found all around the British Isles, is represented by a solitary living example in Jar B, and this specimen is intermediate in form between antiquus and despectus of Linné. In a Paper published by me on Fusus (Journal of Conchology, July, 1890), in describing the var. striata, the following statement occurs :-"This variety also occurs on the opposite side of the Channel, off the Waterford Coast, and some examples are so strongly ridged as to approach in form Fusus despectus, Linné. I entertain the opinion that, if a sufficient number of specimens were obtained, the fact would be established that F. antiquus and F. despectus are one and the same species." Since then other specimens from the same district have occurred, and which are still more strongly carinated. Of one of these Canon A. M. Norman says:-' "I refer it to despectus rather than to antiquus." The specimen in Jar B may be regarded as an extreme form of F. antiquus, var. striata, or as F. despectus with equal propriety. 2. F. despectus, Linn. A dead specimen in Box 4, marked "Station 3, 1885," would be referred to this species by any conchologist who was in ignorance of the locality from which it was obtained. This species is recorded in the Porcupine Report as occurring off the West Coast of Ireland, Stations 10 to 17. The fragmentary specimens obtained in the Porcupine expedition in the locality mentioned are in the Natural History Museum, South Kensington, and I cannot distinguish those specimens from the one under notice. 3. F. islandicus, Chemnitz. One fine live specimen in Jar A, 5:02 inches in length. It is only within the last seven years that this species has been found in the living state in the British Seas, the three specimens found in earlier times-two from Shetland and one from the Wexford Coast-being dead, as recorded in British Conchology, and a doubt existed as to whether they were recent or glacial fossils. During the past seven years some eight or nine living examples have been trawled between the Waterford and Pembrokeshire Coasts, most of which were secured by the writer. The specimen in Jar A, although it has unfortunately lost its embryonic whorls, is the finest example of F. islandicus that I have seen from the British seas. 4. F. gracilis, Da Costa. There are of this common species only seven specimens in the jars, and five of these are dead. In Box 1 there are two distinct forms-one being the type, and the others with strong spiral striæ are varietal. The difference in the sculpture of these two forms is as great as that spoken of in describing Buccinum humphreysianum, var. ventricosum; other species, notably Buccinum undatum, vary in the same way. 5. F. propinquus, Alder. There are, in all, nine specimens, of which four may be referred to the type (three dead specimens in Box 2, and one dead example in Jar F). The remainder furnish, at least, two new varieties which will now be named and described : F. propinquus, var. intermedia, Jordan. The immature specimen in Box 7, "Exp., 1886, log. 44, 108 fms.," is intermediate in form between F. propinquus and F. jeffreysianus, partaking slightly more of the facies of the former. It is an interesting specimen, as appears to connect these two species. L. 1. B. 0.44 inch. it F. propinquus, var. nana, Jordan. A dwarf, solid form. The first five whorls increase more rapidly, and the others less rapidly, than in the type; thus the shell has a sub-cylindrical shape. The penultimate and ante-penultimate whorls are longer, and the body whorl is much shorter than usual. L. 0.94; b. 0:40. This curious little specimen, out of Jar A, was almost entirely invested by an anemone, the end of the canal alone been visible. It was inhabited by a hermit crab, and is returned in a box with this Report. In Box 2 there is a remarkably thick and solid specimen, and in Tube B, Box 3, a similar form. To these might be assigned the varietal appellation of incrassata. This variety also occurs near Aberdeen. 6. F. jeffreysianus, Fischer. The two dead specimens in Jars B and D, and the examples in Boxes 5 and 6, call for no special comment. 7. F. berniciensis, King. Two dead specimens in Jar C-one measuring 4.34, and the other 1.63 inch in length. These are the first specimens which have been recorded from the Irish coasts, so far as I can ascertain, and this fact imparts a special interest to the specimens notwithstanding their bad condition. This species has been taken in the North Atlantic, midway between the Irish and Labrador coasts, 690 fms.; in the Bay of Biscay, Le Travailleur Expedition; and in the slopes of the Channel, 257-539 fms. 8. F. fenestratus, Turton. Three dead specimens in Jar C-two of them measuring 2.12, and the other 1.95 inches in length. During the past twelve months a dead but fresh specimen was trawled between the Waterford and Pembrokeshire coasts, 40-60 fms. Having described the specimens in detail, it may be well to take a brief survey of them in general. The first impression is one of disappointment at their small number and generally bad condition; nevertheless there is considerable interest attached to them. In the first place the Buccinum ventricosum of Kiener-a Lusitanian and Mediteranean form-is new to the British fauna, and its connexion with B. humphreysianum is established. Again, it is in company with F. islandicus—a boreal and Arctic species --and thus affords another illustration of the "interdigitation of faunæ," which has been noticed by former Reporters. (Proc. R.I.A., Ser. 3, Vol. I. p. 42. Then, again, F. berniciensis is new to the Irish coasts, and there are at least two new varieties of F. propinquus. R.I.A. PROC., SER. III., VOL. II. 2 I |