The list of the fish ascertained, as belonging to the Land's End, is now brought to a close. The notes have extended to a greater length than was at first intended, and yet they have been greatly abridged lest I should overstep the bounds at the service of such investigations. From the peculiar and extreme western position of the district, and from its being almost surrounded by water, the opportunities for ichthyological investigations are great, and such as would interest observers in other parts of the kingdom; it is these considerations alone that tempted me to exceed the bounds formerly intended for these

notes.

Penzance.

R. Q. COUCH.

P.S. On the Eggpurse and Embryo of a Species of Myliobatis, by Jonathan Couch, Esq., F.L.S., &c.—Early in the month of August of last year (1845), Mr. Peach was so obliging as to send me a purse or case of the ovum, of what appeared to be a species of rayfish, such as I had never seen before, and which he had obtained from a trawl vessel, that had been fishing, a few miles south of Fowey, in Cornwall.

So little is known of the distinctions of these egg-cases so characteristic of the rays and some kinds of sharks, that it is probable no museum in Europe will be found to contain specimens of even a majority of them; and as the one or two eminent naturalists who have had an opportunity of examining the curious structure of the surface of this specimen were unable to refer it to any of the known cartilaginous fishes, and the accident of finding such a one on a beach may be the only proof of the probable presence of the parent, I have thought it well to give a minute description.

The length of the case was 6 inches; the breadth 43 inches; length of the processes at the anterior angles 2 inches, flat, or thin, and tapering to their terminations; but as the anterior border of the case is concave, these tendrils appear simply as elongations of its surface. The posterior margin is straight; and consequently the origin of the tendrils is better marked. They are narrower than the anterior; and end in a thin and slender cord, their length being 7 inches. I have seen the purse or case of the common skate (R: batis) much longer than this, but in no instance more than two-thirds as wide; and consequently in proportion this is the widest of any. The longer tendrils also exceed in length those of any of the rays that I have seen; though they yield to those of the common oviparous shark (Scyllium

canicula), or that of the large-spotted dogfish or nurse-hound (Scyllium catulus), as represented in Mr. Thompson's figure. But the greater distinction is in the structure of the surface, which in the cases of all the rays that I have examined, is smooth or plain, with a longitudinal direction of the fibre. In the present instance this structure is peculiar and beautiful; the surface being thickly set with raised longitudinal lines, closely crossed with dots or raised lines;—that is, each longitudinal line is very thickly studded with raised marks, points or short lines, which do not pass from one longitudinal line to another, but sink into the minute channels between them. This description, however, applies only to the middle of the surface, for towards the ends and sides the longitudinal lines become thus joined; and the reticulations form fine and beautiful squares, which are still finer on the border; and on the extreme margin they disappear. The colour, when I received it, was very dark, but browner at the borders. There were a few small Serpulæ and Flustræ attached to the surface.

It was a considerable time, after I obtained this case, when I became aware that at the time it was found, it contained an embryo, which on my further inquiry was kindly submitted to my examination. The ovum or yolk, which had been immersed in a bottle of Mr. Goadby's preserving fluid, was as large as an ordinary orange, but somewhat compressed: the foetus comparatively small, and consequently far from being fully developed. The mouth was placed far

under a projecting snout, which rose into an elevated vertex. The eyes large, projecting laterally from the sides of the head. The head distinct, joined to the body by a neck. Pectoral fins with a shoulder, as in the genus Squatina; the anterior angle advancing near to the eyes; their outer margin a little sloped, and passing backward in a direction corresponding with the outline of the body. Ventral fins small and slender. The situation of the branchia is well marked dorsally, with five lines, showing the number of orifices; · branchial fibres long, as in the early state of other embryotic chondropterygious fishes.

The body is narrow, with a dorsal ridge that runs down the caudal portion to the end; and at a third of its length from the body this ridge begins to be bordered, as with a narrow fin, that seems to decrease again as it proceeds. This caudal portion has also a ridge beneath, which begins close to the vent; and on both sides there is a membranous border. The tail is long and narrow, tapering, but without an obvious fin towards the end.

There can be little question that this fish belongs to the genus Myliobatis of Cuvier, which is characterized by having the pectoral expansion separated from the head, which organ becomes thus exserted, after the manner of the genus Squatina, but from which latter, among other important particulars, the present differs in having the mouth placed far beneath the snout. In the adult state also, it is marked by a small dorsal fin, and close behind it, is a lengthened spine situated anteriorly on the caudal elongation. That in an embryotic specimen the dorsal fin should be obscure, is not to be wondered at; for in numerous specimens of several species of the common rays that I have obtained from the egg-case, I have constantly found the caudal elongation to differ much from what is seen in the adult fish ; and I believe that all of them are at that period destitute of the ordinary spines. It is probable that the direction of the expansion in the pectorals, in this species, is subject to variety in different stages of growth; or these parts may have been compressed by the walls of the case; for in Mr. Yarrell's figure of what may be supposed the same species ('History of British Fishes,' vol. ii. second edition), and in one of Gesner's figures, in his Nomenclator Aquatilium, (p. 121)' which is copied from Belon, the pectorals are represented as extended at right angles from the body; while in another, in the same volume, the extremity is directly obliquely backward; as it is also in the sketch taken from the present specimen. It may be from this direction of the wings that this fish has been fancifully compared to a bird; and hence it is denominated a sea-eagle. Ruysch, whose figures are for the most part copies from preceding authors without being improvements on the originals, has at Plate 9, fig. 9 given a tolerably characteristic likeness; and he remarks, that this fish has been called sea-toad, from the resemblance of the form of the head to that creature; and the comparison seems appropriate, from the elevation of its head, and the lateral and projecting eyes. The same author, from his own authority, says that this fish is viviparous; an assertion which the foregoing account shows to be incorrect.

Polperro.

JONATHAN COUCH.

Habits of the Pond Mussel. Having lately had a pond drained to within a few inches of the bottom, I have had frequent opportunities of observing the economy of the Anodon or pond mussel, of which there are great numbers in the mud. Their manner of locomotion, though slow, is extremely regular, their tracks being very discernible in the soft mud. If the Anodon is furnished, as its congeners are, with a bys

sus, it certainly never makes use of it, at least not in this situation, as I have never found any of them attached by it, either to one another or to extraneous substances, to the latter indeed, in this instance they cannot, as the pond is in the peat moor, and there is neither stone nor any other substance on which it could possibly fix itself; in specimens which I have opened I have not succeeded in finding it, although I have in every case observed the small foot, its essential instrument of locomotion. I have never heard any good account of the food of this mollusk, and its manner of eating: from my own observation it appears to protrude a retiform substance through which it very probably takes in animalculæ, or perhaps decaying animal or vegetable matter. The Anodon is found in great abundance in this neighbourhood, as well in the Trent, which at high tides is here salt water as in our ponds and drains. It furnishes a very favourite repast for the herons, which evince great dexterity in opening the shell. attains a considerable size, some I have seen being five inches in length. — E. S. Peacock, Jun; Bottesford-on-Trent, Lincolnshire, March 16th, 1847.

It

A word on long series.

Allow me to enter my protest against the practice which now obtains among our collectors of British Lepidoptera of keeping in their cabinets unreasonably long series of every species. I admit that the old system of having only four or five individuals of a species is not to be defended when such species is variable, but on the other hand, the keeping of twenty specimens answers no scientific purpose when the characters of a species are constant. It may be all very well for those who have no other purpose than making a cabinet a series of pretty pictures, and the contrast presented by whole rows of species may be very gratifying to their feelings. But besides the degradation thus inflicted on science, rare species are confined to the possession of few persons until they have made up their "row," instead of being diffused among and increasing the knowledge of many. I may add, without intending any self-laudation, that if I had kept the fashionably-long series of twelve or twenty, thousands of specimens would now be in my cabinet instead of being diffused through the kingdom, and the collections of my entomological brethren would be to a like extent deficient, at least as far as I am concerned. When speaking to one of the plus gentlemen lately on this subject and showing the folly of the system, the best answer I could get was that Mr. did it, and therefore it must be proper;" and this, I believe, is the best reply that the majority of its adherents could give. In fine, "it is a great evil, which is increasing and ought to be diminished.”—J. W. Douglas ; 19, Nelson Square, Peckham, November 20th, 1847.

66

On the Entomological Zones of the Pyrénées.-At the meeting of the Académie des Sciences on the 10th of May, 1847, was read a paper on the above subject by M. Lèon Dufour.

66

Insects," says the author, "like plants, are amenable to certain meteorological conditions which favour, modify, or altogether prevent their fixed residence in certain determinate zones. I say fixed residence, in opposition to a temporary station—a vagrant and transitory habitation like that of certain Hymenoptera, Diptera, and Lepidoptera, which, during their active aërial existence, are the free denizens of many zones, of which they are never more than the nomadic inhabitants.

"Insects possess a great advantage over plants in being endowed with a power of locomotion, whereby they are enabled to extend their zone of residence; but as a re

sult of the superiority of their organization and its physiological consequences, though chiefly from their sensibility to external influences, they are unable to endure certain low degrees of temperature wherein many plants will grow and perpetuate their species. Thus, at the culminating points where Ranunculus glacialis and Saxifraga groenlandica are found, that is to say at an elevation of about 3000 metres, I have never met with insects permanently established, such as certain Carabites, Curculionites and Forficulites, whose young are freely produced 500 or 600 metres lower down; the entomologist would consequently lose both his time and his labour in hunting for these on the summits of the Pic d'Ossan, of the Monné, of the Pic de Geré, of the Piquette d'Endrellits, the Pic du Midi, &c. He might by chance, on some sunny day towards the end of August, capture a rapidly flying Bombus, which had ventured into those elevated regions to plunder their flowers, or he might meet with a common Syrphus, or a butterfly belonging to the embrowned genus of Satyrus, rapidly traversing such localities and eluding attempts to enclose it in the net.

"The climatal conditions of these altitudes are incompatible with the maintenance of animal life in insects with a permanent domicile. Snow which covers the summits of mountains and their approaches for at least half the year, is opposed to all the necessary conditions of life and means of subsistence of the perfect insect, and more especially to those of the larva, whose power of locomotion is more restricted, and its susceptibility much greater. Thus the region called by botanists the upper alpine zone would yield nothing or next to nothing to entomological researches.

Plants, by the normal development of their periods of evolution, appear to me to define, much better than all the lines laid down upon maps, the general mean temperature and the climatal constitution of localities. Under these two relations, the palm, the olive, the fig, the maize, the vine, the oak, the beech, the birch, the fir, the rhododendron, the Ranunculus glacialis, &c., are to me more significant, more veridical, than degrees of latitude, longitude, and altitude, which necessarily lose somewhat of their mathematical precision when the question of the variable locality of a vegetable or animal organism is under consideration. Vegetation in itself, either directly or indirectly, influences the existence of insects. Those insects which are essentially phytophagous, seldom pass by a plant adapted for their support; and when the particular species best fitted to supply their wants is absent, by an admirable and providential botanical instinct they know how to have recourse to another species of the same genus, or, in default of this, to another genus of the same family. And as to insects destined to feed upon living prey, or to exist in some organic detritus, they also are in like manner amenable to the influence of the harmonions law of nature."

M. Dufour establishes two entomological zones for Pyrenean insects.

"1. The sub-alpine entomological zone. This comprises not only the forests of beech and fir, but the bogs and water, in short all the country below and of an equal altitude with these forests.

"2. The alpine entomological zone. This rises above the pine forests and commences with the rhododendron - the only social shrub of the Pyrénées."— Revue Encyclopédique, May, 1847.

Capture of rare Insects in England and Scotland. It may be useful to your entomological friends to know that the following rare insects have been taken in England and Scotland.

Lophyrus Pini, Linn., Lophyrus pallidus, Illig. I bred both sexes in 1846 from caterpillars collected in Scotland.