On May 12th, 1913, four specimens of the marine leech (Calliobdella lophii) were taken by myself whilst working at the Marine Biological Association Laboratory, Plymouth. The leeches were parasitic on the skin of a large angler (Lophius piscatorius), just behind the gill covers and in front of the pelvic fins, two on each side. The angler was caught in Jennycliff Bay within a few hundred yards of the shore, about 3.15 p.m., half-ebb, and was taken in a small trawl only just large enough to contain it; shrimps were present in the same catch, but no fish.

Calliobdella was previously unknown at Plymouth. The leech was named by van Beneden and Hesse in 1863 from five specimens found in March by Hesse at Brest. Some of the external characters alone were described by them. They omit to mention, however, that the genus is characterised by its having six annuli to each body segment, a point which it shares in common with Ichthyobdella and Pontobdella, but which separates it from other genera. They describe so accurately the beautiful appearance of this leech that their own words suffice:—

“An animal carrying a sucker at each extremity of the body, the posterior very large and simple. The body divided into two distinct regions, a neck region bare, and a region of the body properly so called, this latter carrying laterally rounded tubercles on the segments or cutaneous folds.”

“This species attains a length of five or six centimetres.”

In February of this year Mr. J. H. Orton collected a number of small nereids on the piles of a wharf at the Great Western Docks at Millbay, Plymouth. These he kindly handed over to me for identification, and, along with other material collected at Plymouth in March, they form the basis of this paper.

These nereids proved to be none other than the little-known Leptonereis glauca of Claparède, of which the only specimen hitherto recorded from the shores of this country was found by Major E. V. Elwes at Oddicombe (8, p. 351) some years ago.

While on shore-collecting expeditions in this district it was frequently observed that Echinus miliaris has the habit of associating together in pairs, and sometimes in groups of more than two. The association of these pairs and groups is sometimes so intimate that it is not possible to interpose even the blade of a penknife between the interlocking spines of the urchins. In all cases observed except one, such pairs were placed side by side, but in one particular case the apical region of one individual was almost certainly placed adjacent to the apical portion of the other. In all the collecting expeditions—made at various times of the year between April and August—on which groups were collected, the total number of urchins of all sizes obtained amounts to about 710. Among this number were obtained 84 groups, which amount in all to 189 specimens. In the earlier part of the investigation a group was taken as such if the members were merely fairly close together, but afterwards only those specimens were recorded which were actually touching one another in the manner described above. Out of the total of 84 groups only 27 were actually recorded definitely as touching one another, although some of the other groups may have been touching. Of these 27 closely associated forms all the individuals were ripe except 3 small specimens belonging to two pairs which were recorded as having an immature gonad. The remainder consisted of 19 pairs, 2 pairs, 1 pair, and 3 groups respectively.

The heterogeneous assembly of Decapod Crustacean types classed as “Anomura” is well known to present a wide range of variation in structural features; in fact, the most apparent bond of union between its highly dissimilar sub-groups consists in the still greater disparity which exists between these and members of either “Macrura” or “Brachyura” proper. The Anomura may best be compared with that other heterogeneous group, the Amphibia: each, apparently of aquatic ancestry, has suffered in the unequal contest with a highly specialized offset from the parent-stock (Brachyura-Eeptilia); the survivors of both the ill-fated groups, Anomura and Amphibia, are few in number, varied in type, and probably not closely related among themselves.

Cardigan Bay occupies a considerable portion of the west coast of Wales. It is bounded on the north by the southern shores of Carnarvonshire; its central portion comprises the entire coast-lines of Merioneth and Cardigan, and its southern limit is the north coast of Pembrokeshire. The total length of coast-line between Braich-y-pwll in Carnarvon, and Strumble Head in Pembrokeshire, is about 140 miles, and in addition there are considerable estuarine areas. The entire Bay is shallow; for the most part four to ten fathoms inshore, and ten to sixteen about the centre. It is considered probable that the Bay was temporarily transformed into low-lyingland by accumulations of boulder clay during the Ice Age. Wave action has subsequently completed the erosive removal of that land area, with the exception of a few patches on the present coast-line and certain causeways or sarns. Portions of the sea-floor probably still retain some remains of this drift, and owing to the shallowenss, tidal currents and wave disturbance speedily cause the waters of the Bay to become opaque. The prevailing winds are, as usual, south-westerly, and heavy surf is frequent about the central shore-line. This surf action is accentuated by the large amount of shingle derived from the boulder elay. The action of the prevailing winds and set of dirfts in the Bay results in the constant movement northwards along the shroes of a very considerable quantity of this residual drift material. Where checked by shore contour or river current this drift accumulates to form storm-beaches, which have eventually deflected certain rivers and streams to the northward, as in the case of the Ystwyth at Aberystwyth, the Clarach stream a little further to the north, and the Leri at Borth.

In July, 1912, a paper was published in the Proceedings of the Royal Irish Academy (Vol. XXXI) on the Marine Porifera of Clare Island, by Miss Jane Stephens, in which the authoress gives an excellent account of a new species of Calcareous Sponge, Leucandra cliarensis. In April of the same year I happened to be working at the Marine Laboratory at Plymouth, and my friend Mr. Orton brought me several specimens of a very pretty little calcareous sponge just collected by him at Wembury Bay. I was too much occupied with other work to examine these carefully at the time, but simply preserved them in spirit. Recently I have examined them in detail, and find, curiously enough, that they belong to the species described by Miss Stephens from Clare Island on the west coast of Ireland.

Confusion has reigned in the works of British authors as to the relationship between Plumularia catharina, Johns., and a more simple form, with unbranched stem, found, like the former, on many parts of the coast. Johnston and Hincks, and the majority of their successors, have recorded the simple form, where it was thought worthy of mention, as a “stemless variety” of the former; but examination of the type specimens of P. catharina in the British Museum has proved that a fundamental distinction exists between the two forms. P. catharina is a branched species and bears on each side of a hydrotheca a pair of lateral sarcothecce; the other is a branchless, bristle-like form, bears on each side of a hydrotheca a single lateral sarcotheca, and has been long known as Antenella (or Plumularia) secundaria (Gmelin).

The physical characteristics of the Bay having been set out in the preceding paper, it will not be necessary to repeat that description here, since only special local featureswill be dealt with, as occasion arises. Peculiarities of distribution had been noted for the Trochidæ and Littorinidæ, and it was with a view to obtaining further information as to the operation of local littoral conditions and their effects upon the fauna that these grouops were more particularly examined. These notes detail some of the peculiarities, and outline what are believed to the controlling causes, at any rate for the central area of the Bay. It would be of great interest to know whether similar peculiarities have been, or can be, observed for other areas of coast. The region discussed lies between Gwbert-on-Sea at the mouth of the Teifi, to the south; and a point a few miles beyond Pwllheli to the north. The portion more closely examined extends from near Llanrhstyd, some eight miles south of Aberyswyth, to Mochras, a few miles south of Harlech. Some observations were also made about Portmadoc, Borth-y-Gest, and Pwllheli in the northern part of the Bay, and about New Quay, and the mouth of the Teifi the south, the most southerly being some miles below Cemmæs Head.

In the year 1755 Ellis described in his “Natural History of the Corallines,” as “Alcyonium pulmonis instar lobatum,” a “sea production” from Whitstable, which the fishermen there had brought to him under the name of “Sea-Fig.” As regards the systematic position of this form, he expresses himself only in so far as to place it with the Alcyonians, a group in which were united at that time, along with true species of Alcyonium, Ascidians, Hydroids, Sponges and even Algæ. As a doubtful synonym of his species Ellis put forward the Pulmo marinus of Rondelet (1555), which however has nothing whatever to do with it and indeed cannot be certainly determined. During the following years, Ellis' work was translated into several languages. A Dutch and a French translation, both dating from the year 1756, are known to me, the former by Tak, the latter by Allamand. There is also a German translation by Krüniz dated 1767.