ANNELIDA.

ORDER I.-A PODA.

G. aquaticus, Linn.

TRIBE NEMERTINA.

Genus GORDIUS.

North of Ireland, W. T. East, West, and South, R. Ball.

B. alba, Thompson.

Genus BORLASIA.

Dec. 18, 1843.-Two worms, apparently of the genus Borlasia (Johnston, Mag. Zool. and Bot., vol. i. p. 536) and of the same species, were found on the beach a short way northward of Carrickfergus by Mr. Hyndman and myself. They were lurking under stones between tide-marks. The species may be described as new, under the name of Borlasia alba :-of a whitish colour throughout, excepting behind the eyes on each side, where a reddish spot appears: eyes fourteen; the first four on each side near the margin of the body disposed in a line, and at equal distances from each other; considerably behind them are three at each side disposed in a triangular manner, the base towards the head of the worm: entire length 2 inches when stretched out so that its breadth is

1 line or 1-12th of an inch.

The annexed outline shows the position of the eyes.

B. octoculata, Johnst.

A few specimens agreeing in size and all the scription and figures were obtained with the last.

ous.

1. Reddish spots.

characters with the deCultra, 1848, W. T.

B. purpurea, Johnst. This species, differing little from the last in any external character but that of colour, was procured at the same time, but was much more numerSeveral specimens of this and the other species of the same family here noticed were kept alive for three weeks in a phial of sea-water, and thus afforded ample opportunity for observation. The water was not changed during that period, but the length of time that they would have lived under such circumstances was not ascertained, in consequence of my leaving home. The individuals of this species were about 3 inches in length and perfectly agreed with the description and figures; some had only six, and others eight eyes as stated by Dr. Johnston.

B. olivacea, Johnst.

A worm agreeing in all characters of form and colour with this-having four eyes, and marked with red over the site of the heart; characters

specially named as they are apparently not constant-was procured between tide-marks in July, 1846, at Bangor, Downshire, by Mr. Hyndman and myself. A specimen agreeing with this, except in having eight eyes, was taken with the species noticed as obtained at Strangford Lough in June, but, judging from zoological characters only, I could not think that it was distinct from B. purpurea.

L. longissimus, Sow.

Genus LINEUS.

Capt. Fayrer got an individual of this species, holding on to a bait (the buckie," Buccinum undatum, Linn.) on his long line, when he was fishing for cod, off Portpatrick. _Having put it in spirits, diluted with an equal portion of water, Capt. F. observes "that the contortions of the poor animal were really horrible." Montagu mentions, that one about 8 feet long, which he put alive into spirits, instantly contracted to about 1 foot, at the same time increasing to double the bulk, which originally was about the diameter of a crow-quill," Linn. Trans., vol. vii. p. 73. Judging from this, the present specimen must have been very much larger, as in its present contracted state it is about 3 feet in length, and from 1 to 3 lines in diameter. Its colour is, as described by the author just quoted, dusky brown, with a tinge of green, with five [several] faint longitudinal lines, of a paler colour."

66

A few years ago, a specimen of the Nemertes, about 12 feet in length, was taken on the opposite coast of Ireland, near the entrance of Strangford Lough, by my friend, Mr. Hyndman: in this instance it was found sheltered beneath a stone, at low water. This remarkable worm, the only species of the genus I believe yet discovered, has three generic appellations attached to it; being the Lineus of Sowerby, the Borlasia of Oken, and the Nemertes of Cuvier. Also taken at Killybegs (6 feet in length before being placed in spirits), sent me thence by Mrs. Atherton, W. T. Dalkey; Clifden, Dr. Ball.

M. trilineata, Johnst.

Genus MECKELIA.

This beautiful worm has been dredged by Mr. Hyndman and myself on different occasions in Strangford Lough, and in the open sea at Ballywalter on the Down coast; in every instance it was free.

I received a specimen of this worm taken at Cultra, Belfast Bay. It is larger than Dr. Johnston's, but agrees in every character with his description and figure.

P. lactiflorea, Johnst.

With the last species, two examples of this were procured. The eyes are as described by Dr. Johnston, and consequently the worm would seem to be distinct from Planaria rosea, Müll. My specimens when extended are each about two inches in length and of a yellowish flesh colour. The characters are all as given by Dr. Johnston.

Found also at Bangor, July, 1846.

P. melanocephala, Johnst.

Under stones resting on a rich oozy sand between tide-marks at Gull Island, Strangford Lough, two of this species were obtained in June by Mr. Hyndman and myself. Both were of a pale yellow colour; the one an inch, the other 1 inch in length; they agreed in every respect with the description and figures given in Mag. Zool. and Bot., vol. i. p. 535, pl. 17, fig. 5.

P. armata, Templeton.

North of Ireland, Mr. Templeton.

Genus PLANARIA.

P.cornuta, Müll., Zool. Dan.; Johnston, Mag. Nat. Hist., vol. v. p. 344. Aug. 26, 1844.-Mr. Hyndman dredging to-day off Castle Chichester, just within the entrance of Belfast Bay, and at a depth of from 6 to 10 fathoms, took three specimens on Laminaria. Although the figures of this Planaria in the works cited differ a good deal, I agree with Dr. Johnston in believing them to represent the same species. The Irish specimens as observed at various times were more round in outline than Dr. Johnston's figures, and consequently quite different from those of Müller in that respect. The network of reddish "vein-like ramifications" on a cream-coloured ground renders this Planaria viewed as a whole very beautiful; the multitude of dot-like black eyes on a rich white ground looked very elegant from the contrast of the white to the general reddish hue of the animal. Its progress, as Dr. Johnston remarks, " for a worm is not slow the tentacula were always reflected backwards so as not to be visible in a profile view. The species has been already so fully described that further observations are unnecessary. One which I left gliding about in sea-water, apparently in perfect health, was when I looked at it again after eighteen hours not only dead, but almost wholly decomposed.

P. vittata, Mont.

A single individual of this extremely beautiful species (of which Mon tagu's two original specimens only have, I believe, hitherto been recorded) was taken by Mr. Hyndman and myself when dredging in Strangford Lough on the 1st of October-in size it exceeded Montagu's, being 2 inches in length and 1 in breadth. It was of a whitish cream colour with black lines, occasionally broken or non-continuous, disposed longitudinally over the upper surface of the body, not unlike those which on a whiter ground render so attractive the plumage of the male silver pheasant Phasianus nycthemerus): these lines are from the delicacy of the animal all visible when the under side-which in itself is plain white-is next the spectator; it was surrounded by a border of pure opaque white, which from the transparency of the entire body within, imparted a beautiful finish to its appearance; the two auricular appendages which emanate from the anterior margin exhibit a black line along their basal half posteriorly; eyes could not be distinguished.

This Planaria was in form quite a proteus, and gliding with an easy motion folded itself gracefully over every object that came in its way. Having placed it in a phial of sea-water, one half of the body rested on the bottom and the other against the side, and being thus at the same time horizontal and perpendicular, and presenting throughout its entire length one mass of folds, of which no two were alike in size, it looked as singular as beautiful. Montagu's figure, though correct, gives no idea of the

grace of the original; as usual, his description is admirable; he remarks, that a drawing was fortunately made from his specimens, two in number, upon the day on which they were procured, as next morning they had disappeared, having been dissolved in the sea-water.

Taken by W. T., E. F., and R. B. at Clifden.

P. tremellaris, Müll.

At the end of April I have taken numbers of this species from the under sides of stones in pools among the rocks at Rockport, Belfast Bay. The specimens were rather under the size-"long. 9 lin. lat. 4 lin."-attributed to the species by Müller, but were otherwise identical.

P. rosea, Müll.

At the same time with Planaria cornuta two specimens of P. rosea were taken. This species has not yet a place in the British Fauna, but it was obtained on the coast of Anglesea last autumn by Mr. M'Andrew and Professor Edward Forbes when dredging there. Müller's specimens were from the coast of Norway.

P. flexilis, Dalzell.

April 14th, 1848.-I found at Cultra, Belfast Bay, two Planaria of this species, adherent to the under side of a stone between tide-marks, and brought them home in sea-water to be observed at leisure. When fully extended they are 6 lines long, and at the head 24 broad, becoming thence gradually narrower. Eyes commencing at the distance of a line from the anterior extremity of the body; all extremely minute, but differing in size; disposed irregularly in a somewhat crescentic form on either side a transparent circle. The vessels along the centre of the body are prettily ramified, like those of the genus Glossiphonia, as represented by Moquin Tandon (Monog. Hirudinées, pl. 14, 2nd edit.). Outside this central distribution of vessels, the body, to very near the margin, is most minutely and beautifully ramified all over; the whole worm presenting the appearance of a Glossiphonia, "set"-in jewellers' language-in the centre of a Planaria which broadly expands on every side. This appearance is literally "shadowed forth" in Sir J. Dalyell's figure 2. The colour of one of my specimens, which lived for twelve days in a phial of sea-water, changed about once in thirty-six hours, was during the time transparent, with the central Glossiphonia-like vessels whitish; the ramifications outside them reddish-lilac.

The motion of these Planaria is "very rapid, smooth, continuous, and even," as Dr. Johnston describes that of the Plan. subauriculata to be (Loudon's Mag. Nat. Hist., ix. 16, f. 2), and with which species I cannot but consider the P. flexilis identical. The differences set forth in Dr. Johnston's diagnostic characters of the two, are, that the body of P. flexilis is "semicircular in front," that of the other "obtuse," and that the intervening space between the eyes is like the rest of the body in P. flexilis: but that " a clear circular spot to each of the two clusters of eyes" exists in P. subauriculata. The individuals examined by me are occasionally obtuse, and occasionally semicircular in front, and present themselves exactly of the forms represented by both authors, as well as in innumerable other shapes. The position of the eyes is the same in both the supposed species; the clear "circular spot" to each cluster may either have escaped being recorded by Sir J. Dalyell, or possibly may not have existed in his specimens; mine have both clusters of eyes within one

transparent circle. On full considerations of the descriptions and figures of P. flexilis, Dalyell, and P. subauriculata, Johnston, I cannot-although it is opposing my ignorance to Dr. Johnston's knowledge of the subject-believe the species to be distinct. My specimens agree about equally well with both species. Further, it may be remarked that my specimens have presented the form of Polycelis pallidus, Quatrefages (Ann. Sci. Nat., t. iv. pl. 3, f. 8, 1845), to which they seem nearly allied; the eyes are just as represented in the highly magnified fig. 9 of that species. It was obtained by M. Quatrefages on many parts of the coast of Sicily. was procured in the Firth of Forth, and P. subauriculata in Berwick Bay.

P. stagnalis, Müll.

North of Ireland, Mr. Templeton.

P. lactea, Müll.

The P. flexilis

This species is marked with doubt from the circumstance of its differing in the following characters from P. lactea. The chief central vessel represented in the figure as of about equal breadth throughout, expands in this into an ovate form about the centre of the body-and the ramifications from it, represented as purple in P. lactea, are in this of a rich fawncolour. My specimens are 9 lines in length, when the breadth is 2 lines; eyes pyriform, generally two in number, placed as in P. lactea (a specimen had two at one side, and one eye at the other); colour milk-white, but the main vessel and its ramifications, spreading throughout all the body except the mere margin, imparts a handsome delicate fawn-colour to the animal. All of the many specimens taken were of the same colour; the size already noted marks them as considerably larger than Müller's. When in motion they were generally more elongate (of about equal breadth throughout) than P. lactea is represented to be, but occasionally appeared of the same form as the figure in the Zoologia Danica.

During an excursion round the shores of Lough Neagh at the beginning of August, 1846, when I was accompanied by A. H. Haliday, Esq., this species was found to be very common, attached to stones at the margin of the lake, and to subaquatic plants. It was gregarious, several individuals being generally adherent to the under side of a stone a few inches in diameter.

P. nigra, Müll.

This species was found abundantly in the same localities, and under similar circumstances with the last. With the unimportant exception of being more of a brown colour and of rather less size, they perfectly agreed with the figure in the Zoologia Danica, and also with the description, so far as given. They were when fully extended 3 lines in length; under a high magnifying power a row of black dots appeared closely disposed round the margin of the anterior part of the body. Sir John G. Dalyell figures similar dots in his P. nigra (Observations on Planariæ, fig. 5), but in my specimens there are three for one represented in it—in the description however they are mentioned as numerous.

August 22, 1846.-Three Planaria, agreeing with Sir J. G. Dalyell's P. nigra, and brought from the pond in the Zoological Garden, Phoenix Park, Dublin, with Hydræ, &c., in May last, are now living before me. These differ from the P. nigra of the Zool. Dan. in being of a jet-black, of a much softer consistence, more shapeless, and being able to diminish themselves to a much less size.