COMMON TERN, Sterna fluviatilis, Naumann.

In July, 1865, I shot three.

ARCTIC TERN, Sterna macrura, Naumann.

The Arctic Tern is very late in coming. According to the boatmen, it does not arrive until May 12th, and leaves about September 18th. I think, however, that I have seen them before May. I shall never forget the spectacle of a vast drove, resting upon a spit of sand, at Holy Island. This island is not one of the Ferns it is a few miles farther north, and a separate day must be given up for it. It was the first time I had seen any Terns not upon the wing. This very large flock quite whitened the surface they were resting upon, and when they all flew up, the effect was beautiful. I dare not venture to make even a guess at their numbers.

:

SANDWICH TERN, Sterna cantiaca, Gm.

Selby says the time of their arrival is about the middle of May (Brit. Orn., ii., p. 466), but I saw plenty on the 26th of April. No one can forget them who has once seen their exquisite forms. They are very tame, and it is a great shame to shoot them.

ROSEATE TERN, Sterna dougalli, Montagu.

The Roseate Tern may exist at the Fern islands still in small numbers, but it is a moribund species as far as English stations are concerned. One-possibly the last-was shot at the islands a few years ago, and has found a place in the Dyke Road Museum at Brighton. I saw it when I was there a short time ago. I have also seen another, which in all probability had been a native of the Fern islands, in Mr Newby's collection at Stockton. It was shot a good many years ago, at the mouth of the Tees. I have also examined a nestling and some adult birds, at the late Mr Selby's, which were obtained by that naturalist himself on the islands. Selby's remark, that in his time the Roseate Tern increased, is curious (Zool. Journ., ii., p. 462). His house was an easy drive from the islands, and he availed himself of their vicinity to study their avi-fauna well, as is very evident from the references to them in his work. This makes his testimony of all the more value. It is observations by men upon the spot which are always so valuable. In the case of the Roseate Tern, it seems

that they came and flourished, and sprang up for a time, and then died out. We have no one who can tell us why. We can only hope that, with protection, they may again come to the fore; but then that protection must be given more fully than it is now.

OYSTER-CATCHER, Haematopus ostralegus, L.

I find that these birds clean the limpets out completely, excepting a small portion of the ligament which attaches the creature to its shell. The boatmen told me they could tackle a limpet as big as a crown-piece; those which I examined, which had been cleaned out by them, were about the size of a shilling. There was only one broken. In general they get out the contents without any need of breaking the shell. It was for some time a mystery to me how their blunt bills were inserted between the shell and the rock, until I read in the "Birds of Scotland," (p. 270), that they only detach those which are already raised a little.

PURPLE SANDPIPER, Tringa striata, L.

This favourite Sandpiper of mine is far commoner at the Fern islands and the opposite shore, than at any other place I ever was at. I have seen, I may say, as many as a hundred in one flock, and they were so tame that they passed and repassed within shot of me several times. I have one which was shot at the islands by Selby, in the year 1831.*

TURNSTONE, Strepsilas interpres, L.

Another common and ornamental bird of the islands is the Turnstone. On one of my visits I killed three at a shot. It would be easy to kill four times that number, as they fly across the narrow channels which divide some of the islands. It was on the 27th of April, and one of them by that time was in beautiful summer plumage. I have seen them on the coast of Durham as late as the 6th of July. Sandpipers killed in May are, as a rule, finer in plumage than any killed at their breeding places in June and July.

It is scarcely necessary for me to say that the above makes no pretence to being a complete list of the species which inhabit

* In the Outer Hebrides Captain Feilden and I shot two Purple Sandpipers, on 27th May, 1870, and saw others.-J. A. H.-B.

the Fern islands or pass by them at certain seasons of the year. I have only enumerated those birds about which I found in my notes matter that seemed to me worth recording in the Society's Proceedings.

III.—On Injured Specimens of Rissoa striata. By Mr

DAVID ROBERTSON, F.L.S., F.G.S.

These injured specimens of Rissoa striata that I bring before you were met with in post-tertiary clay taken from an excavation for Paisley Gas Tank. The larger one has been injured about the time of the growth of the fifth whorl, and the body whorl that succeeds takes a bend and swells to an abnormal extent. The most interesting point is that this abnormal whorl is devoid of striation. The process of striation seems to have ceased at the time of the injury, from which we are led to believe that when the animal is in possession of all its faculties it is furnished with a special appliance for the formation of these striae, and when that appliance is destroyed, the striae consequently cease to be formed. Nevertheless, the growth of the shell goes on; but in the case before us it has, from the point of injury, grown out of proportion to the first formed whorls. Now, the question arises, whether the loss of this faculty of striating is the cause of the increase of growth of the shell?

Another shell of the same species from the same locality tends to strengthen this view. It has sustained a similar injury, but to all appearance of less extent, and at an earlier stage of growth. It is also curved at the point of injury in the same manner as the other, and from that point the striations are greatly weakened, although not altogether wanting, and the whorls succeeding the injury have also grown out of proportion. This animal, not having sustained so much injury as the first example, has been still able to continue the striations, although in a weak degree, and you will observe that the striae almost disappear as they approach the outer lip, which we may consider as proving that after the injury the power of striating has rather been declining than recovering.

The great difficulty in this case is the want of a sufficient number of examples to prove satisfactorily that the destruction of the one organ affects the function of the other. In a palaeontological point of view it should be remembered that such cases

may at times fall into our hands, and there can be little doubt that even with recent forms individuals may have frequently been raised to the rank of species, which were nothing more than functionally imperfect animals. This must be all the more likely to happen with fossils where the diagnosis has often to be made from a crushed individual, or a fragmentary portion of a shell. If a body whorl was met with in some of our Carboniferous shales which, under similar circumstances to one of these shells before us, was devoid of its characteristic striae, and enlarged beyond its normal size, it is almost certain that it would be referred to a different species, or described as new.

A discussion followed the reading of this paper regarding the functions of the mantle in molluscs, in which the Chairman, Mr D. C. Glen, F.G.S., and others took part.

DECEMBER 18TH, 1877.

Mr James Barclay Murdoch, Vice-President, in the chair. Messrs. William Horn, Edinburgh, Robert Bennett Browne, and John M. Martin, were elected ordinary members.

SPECIMENS EXHIBITED.

Mr David Robertson, jun., exhibited a pair of Black-throated Divers, Colymbus arcticus, Linn., got on a small islet in Loch Awe in May, 1876. Mr Robertson remarked that these birds were in full summer plumage, a condition in which they are seldom found, especially so far south as Loch Awe. The species frequents principally the lakes of Norway and Sweden, and Hudson's Bay, North America; and in Scotland is chiefly found in the north, where it breeds in the lochs of Ross and Sutherland, and in the Hebrides. In 1850 it was obtained in several parts of England, but so far as is known, in all cases the specimens were in winter plumage. In Ireland it is very rare, having only occurred two or three times. Mr Harvie-Brown, who has often met with this bird in the northern counties of Scotland, made some remarks on the specimens.

Mr Arthur Pratt exhibited a fine series of the heads and stems of various species of Crinoids, from the limestone strata at Invertiel, near Kirkcaldy, and other districts in Fifeshire, amongst

which he had found the two following species, Hydreionocrinus Scoticus, De Kon., and Poteriocrinus nuciformis, M'Coy; and in illustration of his remarks he had prepared enlarged drawings of the different parts, and full sized restorations of four of the many genera comprising this family of Echinoderms. Mr Pratt said the Crinoidea first appeared in the time of the upper Cambrian rocks, and they have continued up to recent times. They flourished in greatest abundance during the Carboniferous period, covering tracts of sea-bottom many miles in extent, and forming strata hundreds of feet in thickness. The drawings of restored forms represented Cyathocrinus, which commenced life in the upper Silurian, and continued through the Carboniferous period; Woodocrinus, which came into existence and perished in Carboniferous times; Apiocrinus, which is found only in the Oolite, having begun and ended in that formation; and Pentacrinus, a Liasic form, which, along with several other recently discovered genera, is still living on the West Indian and Atlantic sea bottoms. Altogether, between 70 and 80 genera, and upwards of 300 species, are catalogued, two-thirds of which are found in Palaeozoic rocks. In the Beith district large tracts of strata many feet in thickness are composed of little else than the remains of Crinoids, but very few heads have been discovered there, only an isolated one turning up now and then on the weathered surfaces. At Trearne quarry the stems are large and robust, the limestone being one of the finest known for building or fluxing purposes. Mr Pratt then described the way in which the bodies of Crinoids are built up, and stated that in the collection he exhibited there were eight different species of heads, and double that number of stems, all differently sculptured on the external surfaces. He had found in an old working near Cupar, about 20 miles from Kirkcaldy, several of these heads and the remains of an Echinoderm, Archaeocidaris Urii, a species which has a wide range in the limestone strata of Scotland, having been first described from the Lanarkshire coalfield.

Mr John Young, F.G.S., and Mr James Thomson, F.G.S., made some remarks on the collection, the former expressing a hope that Mr Pratt, who had already done good work in illustrating this group of fossils, would continue to prosecute what he had so well begun.

The Secretary exhibited a collection of plants from Disco Island, forwarded by Captain H. W. Feilden, C.M.Z.S., naturalist to the