and if she observes you touch or examine the egg, becomes restless, keeping her wings in motion, and uttering a low twitter of uneasiness. The male sits upon the ground during the day, beneath the branches of the vines, and usually commences his evening flight about five or six o'clock. Whilst the bird has been on the wing, I have frequently observed a sudden twist or bend of the head; but, from the quickness of its flight, and from its usually flying high, I cannot confirm or contradict what is advanced in III. 32, 33. [By Mr. Dillon, on the use of the pectinated claw of the nightjar. See also III. 188. 296. 449; IV. 275. 425.] That the South American species have the serrated claw may be seen by the specimen I send. In its stomach I found, on dissection, a quantity of mosquitoes and some coleopterous insects [this is the instance referred to in p. 560.], which were taken, probably, while it was on the wing. I do not think the bill suited to taking beetles upon the ground. These birds leave the neighbourhood of Lima in April or May. The specimen I send was shot at Lurin, about twenty miles from Lima, in the end of July: the species is called “durmidero" by the natives. As I am not well supplied with ornithological books, I shall feel obliged for information whether it be a described species, and, if it be, what it is called. I wish the specimen to be presented to the Linnæan Society for their collection.

So.

Lima, August 22. 1832.

WE are sorry that we have so long withheld Mr. Mathews's communication, and present to him our apology for doing Our motive for the delay has been the wish to get the species identified with some one already described, or get it clearly distinguished as an undescribed one. We have not, even now, succeeded in attaining either object. One ornithologist, to whom we had submitted the specimen and account of it, has replied, "I have searched the different ornithological works to which I have access, but without finding Mr. Mathews's goatsucker. It is probably undescribed." Another naturalist, versed in ornithology, to whom we had sent the specimen and account, has remarked in reply: — "I have here no means of ascertaining its systematic name; but can nevertheless assure you that it is a species very well known, so that a technical description of it would be unnecessary. It is one of those curious species with pectinated claws, but without any vibrissæ on the rictus, the absence of which has occasioned many naturalists to doubt that the former

structure is ever used to clear from the mouth the hooked claws of coleoptera, &c.; but, I think, without sufficient reason, for the beetles might hitch to the rictus as easily as to the vibrissæ, and more so. Mr. Mathews's account of its habits is interesting, and in these it resembles very closely the common species of this country; but one curious circumstance is mentioned, that of its laying but one egg, which, should it prove to be invariably the case, would be a remarkable anomaly in the genus. I wish that its note had been described."

To complete our account of the specimen of Caprimulgus sent by Mr. Mathews, we add a technical description of it, which the ornithologist first alluded to above has supplied.

Length, from the point of the beak to the end of the tail, 8 in.; from the point of the beak to the gape (rictus), seven eighths of an inch; width of mouth across, 1 in. The whole of the upper surface of the back, a speckled ash grey, marked on the top of the head with dashes of black and streaks of the same colour on the back. The general colour of the upper surface of the wings rather lighter than that of the back, beautifully mottled, and various feathers distinctly marked with black at their bases, and yellow at their points. The primaries black, dusky towards the tips, with a minute edging of white. The bird was a male; and the first four primaries are marked with an oval spot of white which pervades both webs. The wing, from the point of the shoulder to the end of the second primary, which is the longest, measures 63 in. The two centre tail feathers are of the same speckled ash-grey colour as the back, but are barred obliquely with black; and, when the tail was closed, these two feathers hid all the others: the outer, four on each side, are mottled over their proximal half [the half nearer the body] with black and white; the distal half [the half farther from the body], black, with the sexual white spot in the centre of the black, extending over both webs. The chin freckled with reddish brown and black. The throat white; this colour extending on both sides to the space behind the opening of the ear. The whole of the under surface of the body and the wings pale rufous brown, transversely barred with dusky black. The under surface of the tail primaries alternately barred with black and white. The bird, in smallness of size, as well as in the want of vibrissæ on each side of the beak, resembles the swallows; but in every other respect is a perfect Caprimulgus, and has the middle toes nearly as long again as the outer ones, with the claw broad and strongly pectinated.

To keep our clew of the notices in this Magazine on certain Caprimulgidæ, mostly the Caprimulgus europæ`us, wound up, we now add V. 726.; VII. 156. 347. and note *, 511. 559, 560. 633., to the references given in V. 674.

In IV. 424., V. 241., VII. 511. 559., objections are expressed to the application of the names goatsucker, Caprimúlgus, and Nyctichelìdon, to the species of birds to which they are applied, as not any species of them either sucks a goat; milks a goat, which deed the word Caprimulgus imputes; or is a night-swallow, strictly speaking, which the word Nyctichelidon, taken literally, implies it to be. O. has remarked, in VII. 511., that a species which visits Lower Canada is called by the inhabitants "the mosquito hawk;" and he has added, that this is " a more appropriate name, as relates to the habits of the bird, than goatsucker." Mr. Mathews has informed us above, that the species which is the subject of his notice had fed on mosquitoes and coleopterous insects. In relation to the name of the species which visits Britain, a correspondent has recently asked as follows:"Would not the name Nyctivociferàtor europa us be preferable to Caprimulgus europæ`us L., or to Nyctichelìdon europæ`us Rennie? All the kinds of the genus Caprimulgus' are addicted to screeching: some in the night.-W. H. Y. Sept. 10. 1834." As we suspect that our correspondent's proposed generic name of seven syllables, the first two Greek, the rest Latin, will scarcely be well received, we may state that he had previously proposed, in a communication, dated July 5., "Vociferàtor europæ us," as the name of the nightjar which visits Britain. "Vociferator," as a generic name, is free from the literary objections to which "Nyctivociferàtor" is subject. All these words about names, which we have for once indulged in, may serve to instance reasons, however humble ones, for the opinion on generic names which Dr. Lindley has expressed, and other naturalists have concurred in. (See VI. 232.) His opinion is this:-" So impossible is it to construct generic names that will express the peculiarities of the species they represent, that I quite agree with those who think a good unmeaning name by far the best that can be contrived."

Previous contributions by Mr. Mathews will be found in II. 67. and III. 431. In VI. 314-319. are figures and descriptions of some marine animals which Mr. Mathews had discovered, and a notice of the fact of his having collected many species of plants in South America, some of them not previously discovered ones, and of Dr. Hooker's having named a South American plant, Mathéwsia foliòsa, in honour of him. Besides Mr. Mathews's attention to, and acquisition of, objects

of these classes, he collects, he has informed us, "nests, eggs, and skins of every kind :" and it is a pleasant duty to remark, that the state of the specimens sent to us fully testifies his skill; the colour and plumage being well preserved, and the skin entire, soft, and flexible. Mr. Mathews, at the date of his communication, stated, that any orders sent to him, might be directed for him, to the care of John MacLean, Esq., Lima; "as my letters will be taken care of, whatever part of Peru I should happen to be in." We received the skin of the Caprimulgus through Mr. Hunneman, 9. Queen Street, Soho, who, we believe, is in professional communication with Mr. Mathews.

ART. IV. Reasons in support of an Opinion advanced, that the Mackerel is not a Migratory Species of Fish. By O.

THE frequent appearance of the mackerel (Scómber Scómber L.) in the shops, at periods of the year when it is not expected, has long induced me to doubt the fact of its being, as Pennant calls it," a summer fish of passage." By reference to my journal, I find this fish has been common in the shops of the London fishmongers, the last winter, during the months of December (1833), January (1834), and February (1834). Now, if the species be migratory, as is generally supposed, these individuals could not, surely, have come from distant seas to our coasts at an unlooked-for period of the year, because the season may have been mild, to go back again on the return of severe weather; for then, it is to be observed, they again disappear. The conjecture I have to offer is, that the mackerel do not, as is the conceived opinion, migrate into distant seas when the spawning season is over; but that they then retire into the vast depths of the ocean, near their spawning quarters, beyond the reach of the lines and nets of the fishermen. I have, for many years, observed, during the winter season, after mild or turbulent weather, that mackerel are invariably to be seen in the shops; and the reason for this appears to me to be, that the instinct implanted in them to visit the shallower water for the important business of spawning, is either matured by an unusually mild and unseasonable state of the weather, or that the violence of the winds has driven them from their deep retreats in the ocean; showing, in either case, that their migrations are not into remote seas. Reasoning from analogy, in natural history, is said [V. 499.] not always to be a safe guide; but the habits of the char (Sálmo alpinus L.) bear no small analogy to the

habits I impute to the mackerel; though I am aware I am comparing a freshwater fish to a saltwater one. When the char spawn, they are seen in the shallow parts of the rocky lakes (in which only they are found), and some of the streams that run into them; they are then taken in abundance: but so soon as the spawning is over, they retire into the deepest parts of the lake, and are but rarely caught. Such, I venture to suppose, may be the habits of the mackerel. This opinion is offered with deference; and it would be a gratification to have it confirmed by some who may have more opportunities for pursuing the enquiry than I have.

Clapton, Sept. 1834.

[OUR correspondent's opinion is quite in accordance with that of a naturalist distinguished in his knowledge of fishes; who, farther, sees in the law of nature which impels fishes to visit the shores periodically, a beneficent provision for the welfare of man, who, without the action of this law, would be deprived of many of those most valuable to him as food.

Our correspondent, the Rev. W. B. Clarke, has mentioned unusual dates of the appearance of mackerel, and other species of fishes, in VI. 291, 292., VII. 197., in his collection of facts relative to his arguments in proof of his proposition of the connection of meteoric phenomena with volcanic emanations.]

ART. V. Illustrations in British Zoology. By GEORGE JOHNSTON, M.D., Fellow of the Royal College of Surgeons of Edinburgh.

26. RETE PORA CELLULO'SA. (fig. 69.)

Synonymes.-Retépora éschara marina Ellis, Corall., p. 72. pl. 25. fig. d. D. F.; Millépora Retépora Pall., Elench., p. 243. (exclus. Syn. Rai syn.); Millépora cellulòsa Lin., Syst., p. 1284.; Turt., Lin., iv. p. 637. (exclus. syn. Borl. Cornw.); Turt., Brit. Faun., p. 205.; Stew., Elem., ii. p. 427. M. foraminòsa Soland., Zooph., p. 138. pl. 26. fig. 2. Retépora cellulòsa Lam., Anim. s. Vert., ii. p. 182.; Risso, l'Europ. Mérid., v. p. 343.

RETE PORA Cellulòsa has been long known as a production of the Mediterranean, where, says Ellis, it is "found growing to shells and rocks, on the Italian shore, in irregular leafy figures, but very often in the form of a cup or drinkingglass, irregularly expanded at the brim." The British specimen here delineated has something of the latter form, and is about an inch in height with a breadth of nearly three quarters: it is affixed by a hollow, thick, and very short stalk, which expands into a shallow cup, with unequal, waved,