opposition of these curves, in Africa, where the quantity of variation is 18 degrees, it decreases with great rapidity, and finally to nothing, in going eastwards to India, or south-westward to South America: and that from the same point, it increases, in going N. N. W. towards Ireland, or to the opposite quarter, towards the coast of Caffraria. But the change is not in any proportion so rapid in the increase, in 2 going north or south, or in the decrease, in going east or west. Such are the outlines of this system; by which, if a person was to set out from Cape Verd, or Cape Blanco, to traverse Africa from W. S. W. to E. N. E. to Upper or Lower Egypt, he would find at setting out, from 15 to 16 degrees of westerly variation, which would increase to 18 degrees about the centre of the Continent, and afterwards decrease to a less quantity than at his setting out. Mr. Park's travels being comprised between Cape Verd, and the centre of Africa, will therefore be in the quarter that has from 16 to 18 degrees; and the part more particularly, where, from the want of observations of latitude, we must depend on his compass bearings, nearer 18 degrees than 17 degrees *.

A

MARINE ZOOLOGY.

"Hast thou entered into the springs of the Sea? or hast thou
walked in the search of the depth ?"

The Greater Spotted, and the Basking Sharks, from Pennant.

N occasional selection of some of the most interesting objects in Marine Zoology, must prove acceptable to professional men ; and will tend to direct their thoughts, when in service, to a sublime source of mental relaxation, and improvement. As a moral writer + observes" Nor must we pass unnoticed, the varieties of animated nature, which the Sea contains. Some of its inhabitants even seem to

In the Atlantic, the increase appears to be about a degree in seven years. In the Indian Ocean, less; and in the Red Sea, there seems to have been little alteration between 1762, and 1776...

The lines, as far as they are founded on authority, are continuous; but broken in the parts assumed.

It is in proof of the existence of this quantity of variation, that, on closing Mr. Park's route at Woolli, there appeared to be only a small deficiency of distance on the map, when 17 degrees variation were allowed. Had the quantity allowed been less, this ought not to have happened, as Jarra is placed according to its latitude.

+ Sermons on the Character and Professional Duties of Seamen, by the Rev. J. S. Clarke, dedicated to Rear Admiral J. W. Payne.

delight in the fury of contending elements; and, by their appearance on the billows, are thought to portend calamity to the Mariner. Others bask on the rugged prominences of the rock, and find their food from plants that grow in the depths of The Ocean." Of the various species of Sharks, we shall first give a description of the Spotted Dog Fish, as they are styled; they are also mentioned by Ray, and Edwards, under the appellation of the Bounce, and greater Cat Fish.

The weight of one of the Greater Spotted, taken by Mr. Pennant, was six pounds three ounces, and yet it measured in length three feet eight inches so light are the cartilaginous fish in respect to their size. The nose was short, and very blunt, not extending above an inch, and an half, beyond the mouth. The nostrils were large, placed near the mouth, and covered with a large angular flap-the head very flat. The eyes were oblong; behind each, a large orifice opening to the inside of the mouth. The teeth small, sharp, smooth at their sides, strait, and disposed in four rows. Both the back fins were placed much behind, and nearer the tail than in common. The tail was finned, and below extended into a sharp angle.

The colour of the whole upper part of the body, and the fins, was brown, marked with numbers of large distinct black spots : some parts of the skin were tinged with red; the belly was white. The whole was remarkably round. The female of this species, and we believe of other sharks, is greatly superior in size to the male; so that in this respect there is an agreement between the fish, and the birds, of prey. They bring about nineteen young at a time. The fishermen believe they breed at all times of the year, as they scarce ever take any but what are with young.

The weight of one of the lesser spotied, was only one pound twelve ounces; the length two feet two inches. This sort of Shark is styled by Ray, Lesser Rough Hound, or Morgay. The head is flat; the nostrils covered with a long flap, the nose blunt, and marked beneath with numerous small punctures: behind each eye is a small orificethe back fins, like those of the former, placed far behind. The ventral fins are united, forming as if it were but one, which is a sure mark of this species. The tail finned, like that of the greater spotted Shark. The colour is cinereous, streaked in some parts with red, and generally marked with numbers of small black spots; but in some they are very faint and obscure:-the belly is white. This species breeds from nine to thirteen young at a time; is very numerous on some of our coasts, and very injurious to our fisheries.

Of the Species in general.

The SHARK, known in Ichthyology by the term Squalus, is a genus arranged by Linnæus under the class of amphibia, and the order of mantes, but by Gmelin is referred to the class of pisces, and order of chondropterygii. There are many species: 1. The Isabella. 2. The Canicula, or greater Dog Fish. 3. Catulus, smaller Dog Fish. 4. Stellaris. 5. Galeus, or Tope. 6. Mustelus, or Smooth Hound. 7. Cirratus. 8. Barbatus, or Barbu. 9. Tigrinus, or Tigre ; about fifteen feet long; Indian Ocean. 10. Africanus, or Galonné. 11. Ocellatus, or Qeillé. 12. Zygana, or Balance Fish-six feet long, weighs 500lbs.-Mediterranean Sea, and Indian Ocean-one of the most voracious: it has an horrible appearance from the teeth, arranged in three, or four rows; broad, pointed, and serrated on both sides. 13. Tiburo, or Pantouflier of Broussonet. 14. Griseus, or Griset. 15. Vulpes, or Sea Fox-remarkable for the great length of its tail, the body being about seven feet, and the tail six feet, long: the upper lobe of the tail is shaped like a scythe inhabits the Mediterranean, the coast of Scotland, and England. The ancients styled this species aware, and vulpes, from its supposed cunning. 16. Longicandus. 17. Glancus, or Blue Shark-about seven feet long-frequent in every sea, and ficrce; but not very destructive in our seas. 18. Cornubius, Porbeagle, or Beaumaris Shark; noticed by the Rev. Mr. Hugh Davis of Beaumaris-length seven feet. 19. Cinereus, or Perlon. 20. Maximus, Basking Shark, or Sun Fish of the Irish-south and west coasts of Ireland, and Scotland, and those of Caernarvonshire, and Anglesea which latter place, they visited in vast shoals during the summer of 1756-inhabit also the Northern Seas as high as the Arctic Circle Long taken for a species of The Whale, until Mr. Pennant pointed out the bronchial orifices on the sides, and the perpendicular site of the tail: they have nothing of the fierce, and voracious nature of the Shark. The dimensions of one found dead on the shore of Loch Ranza, in the Isle of Arran, were—whole length, 27 feet, 4 inches; first dorsal fin, three feet; second, one foot; pectoral fin, four feet: ventral, two feet; upper lobe of the tail, five feet; the lower, three feet. The liver is of a great size, but that of the female the largest :-some weigh above rooolbs. and yield a great quantity of pure oil, fit for lamps, and also much used to cure bruises, burns, and rheumatic complaints. A large Shark of this species has afforded the captors a profit of 201. They sometimes run off with two hundred fathoms of line, and employ the fishers for twelve, and sometimes for twenty four hours, to subdue them there has been an

instance of a vessel of 70 tons being towed away by them against a fresh gale. 21, Carcharias, or White Shark-often thirty feet long, according to Gillius weighs 4000lbs. The mouth is furnished with a six-fold row of teeth; flat, triangular, sharp at the edges, and finely serrated when this shark is in a state of repose, these dreadful teeth remain flat in the mouth; but, when it seizes its prey, this species, like all the rest, possesses the power of raising them upright. It has great strength in the tail; the sailors instantly chop it off when taken. The ancients were acquainted with this Shark, a long account of it is given by Oppian. They are the dread of sailors in all hot climates. 22. Pristis, Scie, or Saw Fish-about fifteen feet long. Is perfectly harmless and inhabits the seas from Greenland, to Brazil, and the Indian Ocean. 23. Spinosus, or Bouclé. 24. Acanthias. 25. Fernandinus. 26. Spinax, Sagre, or picked Dog Fish, takes its name from a strong and sharp spine placed just before each of the back fins, distinguishing it at once from the rest of the British Sharks: grows to the weight of about 20lbs. This species swarms on the coasts of Scotland, where it is taken, split, and dried; and is a food among the common people: it forms a sort of inland commerce, being carried on women's backs, fourteen, or sixteen miles up the country, where it is sold or exchanged. 27. Squamosus, or Ecailleux. 28. Centrina, or Humantin. 29. Indicus. 30. Americanus, or Liche. 31. Squatina, or Angel Fish-from six to eight feet long, with a large head. This fish connects the genus of Rays, and Sharks, partaking of the character of both. Extremely fierce, and dangerous to be approached—is not unfrequent on most of our coasts. The ancients made use of the skin, which is very rough, to polish wood, and ivory; as we do, at present, that of the greater dog fish, Their flesh is now but little esteemed, on account of its coarseness; yet Archestratus (as quoted by Athenæus, p. 319.) speaking of the fish of Miletus, gives this the first place, in respect to delicacy, of the whole cartilaginous tribe. They grow to a great size; sometimes to near an hundred weight. 32. Massasa. 33. Kumal.

Sharks are seldom destructive in the temperate regions: their ravages are most frequent in the Torrid Zone. In the West Indies accidents happen from them almost every day.

[To be continued.]