Genus ROSSIA.

R. Owenii, Ball.

Dublin Bay, Dr. Ball.

R. Jacobi, Ball.

Belfast Bay, Mr. J. Grainger. Dublin Bay, Dr. Jacob.

S. Australis, Flem.

Genus SPIRULA.

"White House, Belfast Bay, Portrush. Templeton, MSS." Magilligan, Mr. Hyndman; Youghal, Dr. Ball; Clare, Professor Harvey.

An individual of this species, and the first Pteropod, I believe, that has occurred on the British shores, was found by Dr. R. Ball on the coast near Youghal, some years ago. At the same time Spirule and Ianthinee occurred, but none of them in a living state.

P. Flemingii, Forbes.

Genus PERACLE.

In shell-sand, Bundoran, Mrs. Handcock. Dredged off Mizen Head, Mr. M'Andrew. South Island of Arran, Mr. Barlee.

In the late Mr. Templeton's Journal, " Doris Argo, Penn., Brit. Zool., p. 22," is mentioned as twice found by him in 1812, on the shore towards the entrance of Belfast Bay; and Dr. J. L. Drummond informs me, that about the same time he procured a Doris here, equalling a hen's egg in size, and which he considered to be of this species. At Youghal (County Cork) it has been taken by Dr. Ball, and to this gentleman and myself has occurred at the island of Ireland's Eye, off the Dublin coast. Professor Allman has favoured me with specimens procured by him at Courtmasherry harbour, County of Cork, where he states that the species is common. The Irish specimens I have seen were generally straw-co

Now separated from Mollusca.-ED.

loured. In one of them the anterior portion of the foot was margined with a line or band of a fine blue colour.

D. repanda.

Alder and Hancock. Annals Nat. Hist. vol. ix. p. 32. A specimen of this Doris was found between tide-marks at Roundstone, County Galway, in July, 1840. Dr. Ball, Prof. E. Forbes. W. T.

D. bilamellata, Linn.

I have obtained this between tide-marks, at the island of Lambay, off the Dublin coast, and by dredging in about ten fathom water, in Belfast Bay. A specimen which was particularly examined was found to agree with Dr. Fleming's description of D. verrucosa in the number of branchial processes, which are 24, and in their arrangement being somewhat "semicircular," in a broadly horse-shoe form, thus In Dr. John

ston's specimens the branchial processes seemed "not much to exceed twelve," and were disposed in an "uninterrupted circle." Annals, vol. i. p. 55. Although the precise number of these organs is of no specific value, the difference alluded to is so great as to be worthy of attention. In a specimen from Newhaven, near Edinburgh, favoured me by Professor E. Forbes, these processes are twenty in number.

D. affinis, Thompson.

Body elongated, equally rounded at both ends, depressed, above closely studded with stout prolonged tubercles, orifices of tentacula without sheaths; branchial processes short, numerous, pinnate.

Length 14inch, breadth equal to half the length: of a very pale straw colour; tentacula without sheaths, short, lamellate, in all respects resembling those of D. tuberculata; cloak covered with long stout tubercles varying in size, the largest along the sides, and of a line in height, generally of equal breadth throughout, but occasionally expanding towards the end, which terminates in a mass or fasciculus of spicula, conspicuous under a low power of the lens, and giving to them the appearance of a spinous armature; margin of the cloak moderately broad, its under surface granulated; space between it and the foot, and also this latter, smooth; branchiæ short, pectinate, about 18 in number, disposed in a broadly horse-shoe form, as in D. bilamellata, and the space within them likewise covered with tubercles.

This Doris approaches D. bilamellata more nearly than any other British species, and would perhaps be regarded by some authors as only a variety of it; for this reason I have named it affinis, to mark that as a species it may be viewed with some suspicion. Compared with D. bilamellata, the D. affinis has more solidity, is somewhat more depressed, its outline of body less elegant, margin of the cloak narrower, tentacula and branchiæ apparently less developed, and instead of the pretty rounded termination which the tubercles of D. bilamellata generally present are fasciculi of spicula, and these not so tastefully disposed over the surface of the cloak as in that species: in all respects it is a less attractive animal.

In the month of December, 1837, I obtained three specimens of this Doris from among oysters dredged at Greencastle, County of Londonderry.

D. Ulidiana, Thompson.

On the 17th of February, 1840, I procured three specimens of this Doris

among oysters brought to Belfast market from the neighbouring coast of Down or Antrim, and after noting their general appearance, colour, &c., set them apart as species unknown at least to the British Fauna. Mr. Alder having some time ago expressed a wish to see my collection of Nudibranchiate Mollusca, it was placed in his hands, and, on this species coming under examination, it was considered by him and Mr. Hancock to be new, and a description of it drawn up for their own use was kindly communicated to me. This is as follows;-within parentheses are my notes on the colour of the living Doris.

Doris Ulidiana. "Length, from spirits, inch, breadth inch; ovate-oblong, rather straight at the sides, depressed [of a uniform pale yellow, the intestines appearing through the skin of a dark colour]. Cloak not extending much beyond the foot, rough with spicula, and covered with large, unequal, obtuse tubercles, the spicula collected in bundles in the tubercles and radiating at their base. Tentacula [long and whitish] lamellated, without sheaths; the edges of the apertures plain. Branchiæ consisting of eleven [beautifully white] pinnated plumes, set in a semicircle round the anus. Foot rather broad. Veil above the mouth semicircular."

On being put in diluted spirits of wine, the tentacula were entirely withdrawn, and the branchial processes lost their beauty by discoloration, which changed them to the same hue as that of the body.

On comparing these specimens at the time they were procured with the most nearly allied species in my possession, the Doris muricata, Müller (Zool. Dan.), they were noted down as being certainly distinct from it :-in being of a more elongate shape, in having the tubercles differently formed, and, in proportion to the dimensions of the body, their being not more than half the size of those of D. muricata. Messrs. Alder and Hancock made the following comparative observations: " Comparing your D. muricata [a species they had not seen before] with our D. aspera and your D. Ülidiana, we come to the conclusion, so far as we can judge from specimens in spirits, that these three are distinct, though nearly allied, species. D. Ulidiana differs from D. muricata in its much larger size, and longer and more depressed form. The tubercles appear to be more depressed, and the branchial plumes larger. From D. aspera it differs also in size and shape; in having larger tubercles, the cloak narrower, and the foot broader."

D. obrelata, Johnston.

Mr. Hyndman procured a specimen of this Doris on Fuci at Skerries, Dublin coast. On its being submitted to the inspection of Mr. Alder, by whom the original specimen described by Dr. Johnston was discovered in Berwick Bay, he remarked that the species "appears to be pretty generally diffused, but nowhere common." He had obtained it last summer in Rothesay Bay.

Doris muricata, Mull.

I have not unfrequently taken this minute species when dredging (accompanied by Mr. Hyndman) in the loughs of Strangford and Belfast; it was generally adhering to the leaves of tangle (Laminaria digitata). Muller describes it as 5 lines long by 3 broad: my specimens were all even under this size. The D. muricata has hitherto been unnoticed in the British seas.

D. aspera, Ald. and Hanc.

Very young examples of a Doris, and most probably (according to Mr.

T

Alder) of this species, were obtained at Glandore Bay, County of Cork, by Professor Allman, in the month of August, 1842. Mr. Alder himself procured specimens of D. aspera, during an excursion with Dr. Farran of Dublin to Malahide, on the coast of Dublin.

Doris pilosa, Mull.

The first Irish specimen of this Doris that I have seen was found in Dublin Bay, by Professor Allman, to whom I am indebted for it; subsequently two individuals were taken by Dr. J. L. Drummond, when dredging in the month of June in Belfast Bay.

D. sublevis, mihi.

D. convex, broadly ovate, smooth, basal sheaths to the tentacula, foot broad, branchial filaments 8, long and finely plumose.

Length of specimen (from spirits) 7 lines; height equal to about half the length; breadth 4 lines; margin of cloak narrow; foot of nearly equal breadth throughout; tentacula long and acuminated. Colour

white.

In being smooth, this species agrees with the D. lavis, Linn., Mull. Z. D. vol. ii. p. 9, tab. 47, figs. 3-5, but differs much in its convexity and in the breadth of the foot, which is represented very narrow in that species. Dredged in Belfast Bay by Mr. Hyndman, September, 1835.

G. elongata, mihi.

Genus GONIODORIS.

G. elongated, narrow; a row of papilla on each side the back; branchial filaments about 10, plumose.

Length of specimen (from spirits) 3 lines; breadth 1 line; height line; breadth of body equal throughout.

This species resembles in form the D. gracilis and D. pallens of Rapp. Nova Acta, vol. xiii. part 2, p. 522, tab. 27, figs. 9 and 10.

I obtained this mollusk in June, 1838, between tide-marks, at the island of Lambay, off the Dublin coast.

G. nodosa, Mont.

Twelve specimens of G. nodosa occurred on a plant of Fucus vesiculosus, dredged in Killery Bay, County of Galway, in July, 1840. Dr. Ball, Professor E. Forbes, G. C. Hyndman.-W. T. Mr. Alder found the species to be plentiful at Malahide in September last.

Var. G.-D. Barricensis, Johnst.

I have been favoured by Professor Allman with specimens of this Doris, of which he procured about a dozen in Courtmasherry Harbour, in the months of August and September, 1838. They were all found among the roots of Laminaria digitata cast ashore, and, being alive, a minute description of them, as observed in this state, was drawn up by Professor Allman. In all details except the following these individuals agreed with those described by Dr. Johnston in the Annals:-Slightly elevated white tubercles, chiefly disposed in straight lines, appeared on the sides of the body; 9 branchial leaflets; in the several specimens examined these do not encircle the vent, but are wanting for the space of of a circle posteriorly, two hinder leaflets shortest.

P. quadrilineata, Mull.

Genus POLYCERA.

Frontal processes of the mantle 4; angles of the foot produced; pair of branchial lobes rather small.

Length of specimen (from spirits) 3 lines; body broadly truncate anteriorly, tapering to the tail; tentacula lamellated; 3 branchial filaments; eyes two, at the inner side of the posterior base of the tentacula. Colour whitish, with the frontal processes of an orange-yellow; a few scattered dots of this colour on the mantle.

Although the four black lines described by Muller as extending in an interrupted manner along the body of P. quadrilineata are entirely wanting in my specimens, I cannot, possessing as they do every other character in common with it, regard them as of a different species. They are at the same time quite distinct from the supposed varieties of P. quadrilineata figured in table 138 of the Zoologia Danica.

Three individuals of this species occurred to us on the same occasion as the Tritonia lactea, when dredging at the entrance of Strangford Lough; they were adhering to Laminaria digitata. When placed in a phial of sea-water, they were generally to be seen suspended by their threads from the surface, the body at the same time moving freely about with much grace. This species has hitherto been unnoticed in the British seas.

P. typica, mihi.

P. with 4 frontal appendages, tapering towards the point; tentacula lamellate; branchial lobes very large.

Length 5 lines; body narrow; tail tapering; branchial filaments elongated, in a tuft anterior to the lobes; disk thin and flexible at the edges. Colour whitish, tentacula and branchial lobes tipped with yellow; back and sides thinly studded with tubercles (spots ?) of a yellow colour, three of which are in the middle of the back, and six or seven close to the tuft of branchial filaments; the intestines (seen through the skin) of a dark colour.

Of this well-marked species, two individuals were dredged in Strangford Lough by Mr. Hyndman and myself, in January, 1835, at the same time with Euplocamus plumosus. They seemed partial to coming to the surface of the water in which they were for some time kept, and to moving along with the foot upwards.

P. ocellata, Ald. and Hanc.

Mr. Alder, by means of the dredge, took this species commonly, and of all sizes, in Dublin Bay, in August last, and subsequently obtained a specimen at Malahide.

P. citrina, Alder.

Mr. Alder dredged two or three specimens of this species in Dublin Bay, at the same time with the last.

P. cristata, Alder.

Obtained with the preceding two species: common.

Genus EGIRUS.

E. punctilucens, D'Orbigny.

Professor Allman obtained this Polycera in a pool at Courtmasherry Harbour, County Cork.

E. claviger, Mull. sp.

Genus EUPLOCAMUS.

Body elongated, tapering to the tail; three plumose branchial filaments.