several interesting facts have been established which may be of future importance in their collateral bearing upon matters of more general interest and importance than the mere discovery of isolated species or forms. In regard however to one entirely new form, there are some points of peculiar interest to which I shall presently take an opportunity of referring.

I have thought it best to consider the species procured under three heads. Of the species found in the northern cruises of Mr. M'Andrew, in the first instance alone, and afterwards accompanied by Prof. Forbes, I will enumerate those found in water under twenty fathoms; and secondly, those in water above that depth; and thirdly, those which have been found in the excursion which these gentlemen have recently concluded along the south-western coast. The following is the list of the more interesting species found principally in Loch Fyne, in water under twenty fathoms. Of the natatorial type of the Brachyura we have only two species, Portunus corrugatus and depurator; and amongst the Macrura, Pandalus annulicornis, and a new species of Hippolyte, to which I propose to give the name of H. Mac Andreæ. In deeper water the forms are more interesting. In Loch Fyne we have Ebalia Pennantii; off Zetland Ebalia Cranchii, a species first discovered on the south-west coast; Eurynome aspera occurs off the Isle of Man; Atelecyclus heterodon, Lithodes arcticus in Loch Fyne, off the Isle of Man, and off the coast of Zetland; Galathea nexa and its near ally Munida Rondeleti (G. rugosa of authors), both in deep water off Zetland and in Loch Fyne; and here I would make a remark or two on these two species. The localities in which they were found upon this occasion prove them both to be deep sea species, which other observations have also shown. I would also remark that the possession of a new species closely allied to our native species of Leach's genus Munida, procured by my friend Mr. Darwin in his voyage, clearly shows the propriety of Leach's having separated generically the Galathea rugosa from the other species of that Fabrician genus; and as the latter is absolutely more rugose than the species originally so designated, I have thought it proper to assign to it a new specific appellation, and have given it that of Rondeleti, after the first naturalist who distinguished and figured it. Of Galathea nexa I have only to remark, that there is no one character to indicate any difference in its habits from its immediate congeners, G. squamifera and strigosa, and yet both the latter are shore species, where, as far as I know, G. nexa is always found in deep water. On the latter species was found a parasite of the genus Bopyrus, which will probably prove to be a new species. Crangon_Cata•phractus (Pontophilus spinosus of Leach) was found off Zetland, and to these I have to add Leachia lacertosa of Johnston. But by far the most interesting of all the acquisitions of my friends in their northern cruises, is the discovery of an entirely new genus of the fossorial type of the Macroura, belonging to the family of the Thalassinidæ, but differing in many important characters from all known genera of that group. In the first place, instead of the monstrous and abnormal character of the first pair of thoracic members, we find them here of nearly the normal construction of the higher and more typical macrourous forms. But the most remarkable circumstance connected with this animal has yet to be mentioned. It was found in one instance at the depth of no less than 180 fathoms, and as at this great depth it is also fossorial amongst sandy mud, we can scarcely imagine of what use any organs of vision could be to an animal so situated. I find accordingly, that although it possesses eyes, they are of no avail as organs of distinct vision, as they possess no pigment, nor, as far as I have observed, have they corneæ; and I presume that the other parts essential for high powers of sight are also wholly wanting. Amongst a collection of the crustacea of the coasts of Ireland, formed by Mr. Thompson, and which he has obligingly placed in my hands, I found a pair of peculiar claws of some species of crustacea with which I was wholly unacquainted; they were taken from the stomach of some deep-water ground-feeding fish, and I now discover that they belong to the species in question. Mr. M'Andrew took it alive in Loch Fyne and the Mull of Galloway, by the dredge; and that gentleman and Prof. Forbes afterwards obtained it off Zetland.

The recent cruise of my friends round the western coast has been fruitful in the acquisition of species of interest, although only one addition has been made by it to the list of English crustacea. The more usual species, Stenorhynchus tenuirostris, Atelecyclus heterodon, Portunus depurator and pusillus, Gonoplox angulata, Eurynome 1846.

G

aspera, and Ebalia Pennanti, require only to be enumerated. Xantho rivulosa, recently discovered to be a British species, is also included. In addition to Pagurus Prideauxii, I find also two of the new species of Pagurus, which I have recently described; of these two, P. lævis was first discovered by Mr. Thompson on the Irish coast; the other was found off Plymouth by Mr. Cocles, and first described by me under the name of P. Forbesii. Lithodes arctica, a northern form, is also in the present collection; but the most interesting amongst the fruits of this little expedition is a fine specimen of a species of the natatory type of the Brachyura, a Portunus entirely new to our fauna, and which appears to me to be P. longipes of Risso, a Mediterranean species. It differs from the only specimen I have in my collection of the latter species, but this may arise from my Mediterranean specimen being very

young.

On the Structure of the Pycnogonidea. By Dr. CARPENTER.

The President exhibited a specimen of a beetle (Blaps mortisaga), which has been found imbedded in some artificial concrete, where it must have been at least sixteen years; and yet, when the animal was brought to him, it was alive, and lived for six weeks after.

Dr. Carpenter gave an account of his researches on the microscopic character of shells, and also the results of his attempts at representing natural history objects by means of photography.

On the Dissimilarity in the Calcifying Functions of Mollusks, whose organization is in other respects similar. By L. REEVE, F.L.S. &c.

Each of the four shell-secreting kinds of Cephalopods-the Cuttle-fish, the Paper Nautilus, the Pearly Nautilus, and the Spirule or Ram's Horn-exhibits a different method of forming its shell, (this shell differing in microscopic structure, and secreted from different parts of the system,) although strictly allied in all those elements of anatomical detail which constitute the soft parts or animal frame. Whilst the calcareous portion of the Cuttle-fish is merely represented by an internal bony plate, consist ing mainly of carbonate of lime, the shell of the Pearly Nautilus constitutes a huge mechanical apparatus, secreted from the mantle enveloping the visceral mass, and consisting of two separate deposits-an outer crust, and an inner nacre-for the purpose of buoying up its inhabitant under the different mutations of pressure to which it is subjected in its deep region of habitation. The shell of the Paper Nautilus, on the other hand, is a light elastic boat, transparent and permeable to light, secreted only by the female for the purpose of oviposition; and in this animal the office of calcification is transferred, by some mysterious order, from the mantle to the hinder pair of arms. The Spirule is again totally different, it being contained within the mantle of an animal, far larger, in proportion, than that of the other Cephalopods, under circumstances which are at present unknown. The drawing exhibited was taken from a living specimen, recently collected at New Zealand, by Mr. Earl, for the first time in perfect condition; but, as the proprietor is unwilling that it should be dissected, Mr. Reeve could only state that it enclosed a problem in the physiological history of the Cephalopods, which it was extremely desirable to solve. The next point to which he directed the attention of the Section was the curious difference which occurs in the growth of the Cowry and the Olive; but this he had already more fully communicated to the Linnean Society.

On certain Peculiarities in the Anatomy of Limax Sowerbii.

By Prof. ALLMAN, M.R.I.A.

The peculiarities of structure in this animal are chiefly to be found in the reproductive system, which in several respects presents a remarkable similarity to that of Helix. There are well-developed multifid vesicles, and an elongated sac containing a singular organ in the form of a curved cylinder beset with numerous palmate spines.

This sac, as well as the multifid vesicles, of which there are four sets, opens into the common sac of generation.

Notices of some new and rare British species of naked Mollusca.
By JOSHUA ALDER and ALBANY HANCOCK.

The first species was a small mollusk belonging to the order Inferobranchiata. This animal closely resembled the animals figured by M. de Quatrefages under the generic names of Pelta and Chalides, and placed by him as the lowest forms of his new order, Phlebenterata. This animal strongly resembles the Limapontia nigra of Dr. Johnston; but whether it be identical with that animal or not, the authors were fully convinced that its characters had been imperfectly understood by M. de Quatrefages. The other naked mollusks found by the authors were a new species of Eumenis, Eolis Drummondi, Eolis alba, and Goniodoris castanea.

On the Hybernation of Snails. By Rev. T. RANKIN, M.A.

From the author's observations on the habits of Helix hortensis, he concluded,-1. That snails hybernate. 2. That in their state of hybernation they undergo less torpor than some other animals which hybernate. 3. That they are destructive to trees as well as to plants.

Mr. Wollaston read a notice from Mr. William King of some new species of animals found on the coast of Northumberland.

Mr. R. Patterson exhibited specimens of Ascidians which he had discovered in the links of the chain of the floating bridge at Itchin, near Southampton,

A few Notes on the Land Mollusca, Zoophytes, and Algae of the Isle of Wight. By W. THOMPSON.

The object of this communication was to inform naturalists visiting the island what species they might expect to find in the classes indicated, which are less known than the other departments of its natural history: lists of these were given. Rare and interesting species were noticed, and the localities where they had been obtained by the author particularized. Freshwater Bay and the adjacent coast to the east of it, were stated to be the best localities for the marine invertebrate animals and Alge. Of land mollusca; the Pupa secale and Bulimus acutus were specially noticed. Of Zoophytes; the Anguinaria spatulata was found commonly investing the stems of various Algæ on the south coast of the island. Of Algæ; the Griffithsia simplicifilum was obtained plentifully at Freshwater Bay, in August 1841, by Mr. R. Ball and the author-the first time of its being noticed elsewhere in the British island, than on the coast of Wicklow.

Additions to the Fauna of Ireland, including Species new to that of Britain. By W. THOMPSON*.

These additions comprised about fifty species of vertebrate and invertebrate animals. Those unrecorded in the British Fauna were the purple water-hen (Porphyrio hyacinthinus), obtained in the county of Kerry by Richard Chute, Esq.; the Tellina balaustina, and Pleurotoma striolata, both known as Mediterranean species-the former procured by Mr. Barlee, the latter by Mr. M'Andrew, on the western coast of Ireland; Botrylloides albicans (Edw.), and B. rotifera (Edw.), collected on the coast of Down, by the author; and Pontobdella lævis (Blainville). A new Actinia of the genus Corynactis (Allman) was noticed; and two new species of Amorphozoa (Sponges), and a Daphnia, believed to be undescribed, were stated to have been obtained. Dysidea? papillosa" (Johnston), whose place in the system had been uncertain, was lately ascertained by the author to be a helianthoid zcophyte, of the genus Zoanthus (Z. Couchii).

* Published in detail in the Annals of Natural History for Nov. and Dec. 1846 (vol. xviii.).

Zoology of Lough Neagh, compared with that of the Lake of Geneva.
By W. THOMPSON; the Insects by A. H. HALIDAY.

The respective areas of Lough Neagh and the lake of Geneva, and their physical, &c. differences being first noticed, a comparison was given of as many portions of the subject as the published memoirs on the zoology of the Swiss lake afforded data on, including the birds, fishes, mollusca, and certain families of the insects. A brief notice of the Crustacea and Annelida of Lough Neagh, and some remarks on the botany of its shores and waters, concluded the paper.

Notes on the Natural History of Corfu. By Captain PORTLOCK, R.E.

On the Pulmograde Medusa of the British Seas. By Prof. E. FORBES. At the Birmingham Meeting, in 1839, the author, in conjunction with Prof. Goodsir, brought forward a first essay towards an investigation of the British Acalephæ, selecting the ciliograde species for illustration. Since that time he has yearly availed himself of every opportunity of pursuing the inquiry, but has abstained from publishing, hoping to gain more complete knowledge of a difficult and much-confused branch of zoology. Having now however examined more than twice the recorded number of British Medusæ and become acquainted with numerous new specific and several new generic forms of great interest to the naturalist, he ventures to lay before the Section an outline of the data in his possession. These data are in great part due to the opportunities afforded him by his voyages round the coasts of Britain with his friend, Mr. M'Andrew. After pointing out the difficulties attending the study of these animals, and giving a brief view of the present state of the subject generally, Prof. Forbes insisted on the necessity in future of naturalists abstaining from publishing imperfect observations respecting them, and urged the adoption of the descriptions of Milne-Edwards, Sars, and Will as models for those who were ready seriously to engage in the study. He called attention to the important observations on their development lately made by his friend Prof. Reid of St. Andrews, and expressed a hope that ere long the return of the Arctic Expedition would bring a great mass of new materials of the most accurate description through the observations of Mr. H. Goodsir. In grouping the British species, Prof. Forbes calls attention to the mutual correspondence of certain characters; viz. of the condition of the reproductive, digestive, and sensitive systems. He proposes to group all the British Medusa under such as have hooded and such as have naked ocelli. The first character is combined with a conspicuous and comparatively complicated reproductive system, and a ramified gastrovascular apparatus. All the Pulmograda with naked ocelli have simple vessels, with one exception,-a new and most beautiful generic form, the type of a subsection by itself. The remainder form three natural groups, as will be seen in the following general table, exhibiting the arrangement of the British Pulmograde Medusa:

1st SECTION.-Hooded-eyed; ramified gastrovascular system.

1st Genus.-Rhizostoma (Cuvier). 1 species, R. Aldrovandi.
2nd Genus.-Cassiopea (Peron). 1 sp., C. lunulata.

3rd Genus.-Pelagia (Peron). 1 sp., P. cyanella, one of the most phospho-
rescent and beautiful of European Medusa, now first announced as British,
having been taken during the past month by Mr. M'Andrew and Prof.
Forbes off the coast of Cornwall.

4th Genus.- Chrysaora (Peron). 1 sp., C. hysoscella.

5th Genus.-Cyanea (Peron). 2 sp., C. capillata and C. Lamarckii, both common; very large, stinging Medusa.

6th Genus.-Medusa (Linnæus, Eschscholtz-Aurelia, Peron). 2 sp., M. aurita and M. cruciata (the latter is the Medusa so abundant in Southampton Harbour). It has white ocelli.

Many more spurious species of Cyanea, Medusa, and other genera are recorded by Peron, Lesson, and others, and enumerated as inhabitants of the British Channel. After careful consideration, they have been rejected as mere varieties from this

arrangement. Certain forms belonging to this section recorded by Pennant and Templeton are also rejected as too imperfectly observed to be of any service to science.

2nd SECTION.-Pulmograda with naked ocelli.

1st Family.-Vessels branched.

7th Genus.-Willsia (new, sp. W. stellata founded on a beautiful little Medusa with six starlike ovaries and branched vessels. It is abundant in the British Channel and on the west coast of Scotland.

2nd Family.-Vessels simple; ovaries convoluted and lining the pedunculated stomach.

8th Genus.-Turris (Lesson; Eirene, Eschscholtz), 2 sp., T. digitale of O. Fabricius (Zetland) and T. neglecta, Lesson, the Cyanea coccinea of Davis; British Channel. Very highly-organized Medusa, closely approaching Ac

tineæ.

9th Genus. Saphenia (Eschscholtz). 1 sp., S. dinema, Peron. Devon, Zetland. 10th Genus.-Oceania (Peron-Tiara, Lesson), 4 sp., one being the Geryonia octona of Fleming; the other three are new.

3rd Family.-Vessels simple, ovaries in the course of the vessels, on the subumbrella.

a. With eight vessels.

11th Genus.-Equorea (Peron), or perhaps deserving of a distinct appellation; 1 sp., common on the Scotch coast; it is the "Milicertum campanulatum" of Ehrenberg (not of Eschscholtz), "Oceania octocostata" of Sars, and "Thaumantias Milleri" of Mr. Landsborough, and “Equorea octocostata” of Lesson. It has long yellow ovaries.

12th Genus.-Circe (Mertens). Ovaries 8 minute. 1 sp., C. rosca. Zetland,

new.

b. With four vessels.

14th Genus.-Thaumantias (Eschscholtz); ovaries four, ovate, clavate or linear, stomach short; 19 British species, of which 12 are new and undescribed. All very distinct from each other.

15th Genus.-Slabberia (new), founded for a singular little Medusa remarkable for its extremely linear ovaries, long proboscis, and the development of an ocellated bulb at the end as well as at the base of each tentacle, S. halterata; coast of Cornwall.

16th Genus.-Geryonia (Peron), 1 sp., new, G. appendiculata. British Channel. 17th Genus. Tima (Eschscholtz?)—T. Bairdii of Johnston; common on the east coast of Scotland.

4th Family.-Vessels simple; ovary in substance of peduncle. Gemmiparous. A. Peduncle with lateral lobes; tentacula fasciculated.

18th Genus.-Bugainvillia (Lesson-Hippocrene Brandt), with 4 fascicles of tentacles. 3 sp., 2 new.

19th Genus -Lizzia (new, with 8 fascicles of tentacles and unequal lobes to peduncle), founded for the Cytalis octopunctata of Sars, which, with two other undescribed species, inhabits the Zetland seas.

B. Peduncles inflated; tentacula not fasciculated.

20th Genus.-Moodeeria (new). 1 sp. from the Hebrides.

C. Peduncle elongate; tentacula not fasciculated.

a. With four tentacles.

21st Genus. Sarsia (Lesson). 4 British sp.

b. With one tentacle only developed.

22nd Genus.-Steenstrupia (new), 3 sp.

In all there are fifty species of British Pulmograda known to Prof. Forbes, excluding doubtful forms and varieties. Of these, fifty-nine only had been previously recorded as British, and of the remainder all but five are undescribed.

Prof. Forbes also exhibited some living specimens of the Lancelot (Amphioxus lanceolatus of Yarrell), of a Holothuria, and of a Medusa found in the Southampton Water.