AUSTRALIAN MUSEUM SCIENTIFIC PUBLICATIONS Laseron, Charles Francis, 1948. New South Wales Marginellidae. Records of the Australian Museum 22(1): 35–48, plates v–vi. [30 June 1948]. doi:10.3853/j.0067-1975.22.1948.588 ISSN 0067-1975 Published by the Australian Museum, Sydney nature culture discover Australian Museum science is freely accessible online at http://publications.australianmuseum.net.au 6 College Street, Sydney NSW 2010, Australia NEW SOUTH WALES MARGINELLIDAE. By CHARLES F. LASEI;0N. Honorary Correspondent, Australian Museum, (Plutes V-VI.) Marginella is common in, but not confined to Australian seas, About a thousand species have been described, many from the tropics, but the majority from temperate waters of the southern hemisphere, In Australia, particularly in the south, they form a conspicuous element of the marine molluscan fauna. The most complete list of Australian species is that published by Bernard C, Cotton,' of the South Australian Museum. He lists 92 species, including several that are new. Fifteen more new species are now added from New South Wales, and no doubt a numbe:r 'Still remain to be described, particularly from Western Australia, north Australia and Queensland. It is interesting to note that most of the described species have a fairly wide geographical distribution, and many are common to several zoo-geographical provinces. As is to be expected, there is a somewhat closer relationship between New South Wales species with those of Tasmania, than with those of the Flindersian fauna (Victoria, South Australia and the southern portion of Western Australia), but many species are common to all three areas. It is very probable that Marginella, like Cypraea, has a free swimming larval stage of some length, and is thus able to migrate more rapidly and widely than most other molluscs. The number of species occurring in New South Wales is probably not yet completely known, as no doubt more will be found, particularly on the continental shelf. Hedley's "Check List of New South Wales Mollusca", published in 1917, allowed 27 species. In the present paper 45 species and three varieties are dealt with, and four of Hedley's list are regarded as doubtful. Of these, 23, or practically one-half, occur in Tasmania, 19 in Victoria, while only 10 are found in South Australia. The total number of species in each of these areas is about 50, Australian tropical species are fewer in number, and. practically none of them are common with species from the colder waters of the south. Practically nothing is known of the life history of Marginella, and the animals of only two Australian species have so far been described. In 1916, Hedley described both the animal and radula of M. 1nustellina Angas; and in 1944 Cotton described the animal of his own species, M. weedingi! As the former inhabits the reefs in shallow water, and' the latter is a deep-water dredged species, it is interesting to note that the general characters of each animal are much the same. There is the same long, narrow foot, blunt head, prominent tentacles with eyes at the outer base, long siphon and mantles at either side covering the shell. In M. mustellina the mantles are papillate, whiIe in weedingi they are covered with small divided processes. These descriptions are very close to that of the animal of the Cypraeidae, with which family Marginellidae is evidently closely related. M. mustellina and M. angasi are inhabitants of the reef, and 11f. nympha is common on seaweed, but most species are essentially sand living, and are found from the edge of the beach to very deep water beyond the continental shelf. It may be noted that the 1 Cotton.-South Australian Natul'alist, Vol. 22, No. 4, Nov. 30, 1944. 2 Hedley.-ProG. Linn. Soc. N.S. W., xli, 4, 1916, p. 709, PI. I, figs. 30, 31. 3 Cotton.-Loo. cit., p. 16. 36 RECORDS OF THE AUSTRALIAN MUSEUM. animal is extremely active, a characteristic of many sand-living forms, particularly the carnivora. Species are rather restricted to depth zones, and those living on the open beaches just below low water are seldom found in deeper water. Depths from about 5 to 20 fathoms have characteristic species, though it was noticed in Jervis Bay that species from five fathoms were quite different from those from 15 fathoms, even though the nature of the bottom was identical. Again, in 20 to 60 fathoms, on the continental shelf, another distinctive group of species is to be found; while from the few really deep water dredgings, still further species have been found. One genus or many? When the number of species in any genus is very large, many modern systematists have advocatlld its division, largely on the grounds of convenience. <The view is held here that unless very definite generic characters can be given the procedure is not only unscientific but defeats its own end by creating a confused and unwieldy nomenclature. Mqrginella is a case in point. At first sight it would seem to be divisible into fairly natural groups, but there are too many intermediate species to make these groups hard and fast and to warrant new generic names. Cotton in his paper has used such groups as a guide to the student of local species, and this is all that is necessary, at least until our knowledge of their anatomy and life history is much further advanced. Be uses seven groups, designated from A to G, based mainly on the length of spire, general form, and presence or absence of colour bands. This is a convenient subdivision as far as it goes, but, as he himself recognizes, not definite enough for generiC separation. A more important character, which may have genetic value, is the number of plications on the columella. What does seem a natural group is a series of small shells, ,centred around M. angasi, with the columella multi-plicate. In most species the number of plications is four, and species .with six or more, occupying the greater length of the inner margin, stand out from the others. Some species have less than four pHcations, but in these, rudimentary folds are often present right inside the aperture, and invisible from in front. Another group which may later justify generic separation is that about M. ovulum, in which the shell is entirely involute, and the spire invisible< externally. I have not followed Cotton's grouping in this paper, as the smaller number of !lpecies dealt with does not necessitate it. The species nevertheless are arranged so that, as far as possible, allied forms are kept together. They are all figured, and a glance at the plates will show the gradual transition from one extreme form to another. Fortunately in this controversial subject there is one point which seems reasonably sure. Whatever future classification is decided on, each species dealt with here is undoubtedly a Marginella. Acknowledgements.-Much of the credit for the collection .of material for this and future papers goes to my son John, who has been my companion in all collecting trips, and whose keen eye has· brought to light many finds. Mr. T. Iredale, formerly Conchologist of the Australian Museum, has continually helped me from the store­ house of his great knowledge and experience. To Miss J. Allan, the present Conchologist, my thanks are particularly due. It was Miss Allan who suggested that I should write up the material collected in the last twenty years; she has looked up references for :me, made suggestions, and finally read through and checked the paper itself. Types.-All types, as well as specimens illustrated, have been presented to the Australian Museum, where they will be available for future reference. REVIEW OF SPECIES. References. Hedley, 798.-The number is that in Hedley's Check List of N.S.W. Mollusca, Supplement to Journ. Roy. Soc. N.S.W., Vo!. LI, 1n7. May, 695.-Number in May's Check List of the Mollusca of Tasmania, Govt. Printer, Hobart, 1921. NEW SOU'l'H WALES MARGINELLIDAE-C. F. LASERON. 37 Marginella turbinata Sowerby. (PI. v, fig. 1.) Hedley 798. This is one of our commonest species, mostly found on the outer beaches. It apparently lives in the sand below low tide, but ranges into deeper water. The ribbing on the shoulder is characteristic, but varies somewhat, as some specimens are practically smooth. Localities.-Fifteen fm. between Heads, Port Jackson, the specimen figured 9·5 mm. in length; Cronulla and other beaches; 14 fm. off Long Reef; dredged in Pittwater;. 30-35 fm. off Crookhaven. .Marginella turbinata var. pusilla, var. novo (PI. v, fig. 2.) In the Roy Bell Collection in the Australian Museum are specimens from 60 fathoms, Twofold Bay, indistinguishable from turbinata, except that they are much smaller, the specimen figured being only 6'5 mm. in length, and somewhat broader. The ribbing is also a little more pronounced. Specimens of turbinata from 30-35 fathoms off Crookhaven, are somewhat intermediate in character, and it seems that this species in deeper water tends to become smaller and broader, denoting racial but not specific difference. From South Australia, Cotton has described M. pattisoni from shallow water, a species which. greatly resembles this variety. Further collecting from intermediate localities may link pattisoni with turbinata, which is a variable species, and which may possibly be divisible into many local races. Marginella olivella Reeve. (PI. v, fig. 3.) Hedley 790. Localities.-Dredged North Harbour, the specimen figured 6·5 mm. in length. This specimen is yellowish with a white base, and a white band near the top of the whorl. Pure white specimens were abundant associated with injelix in 6-9 fathoms, Sow and Pigs Reef, and it was also taken alive in 15 fathoms, Jervis Bay.