LAMNID^E. 305 



considered the forms known as Poh/prosopus, not as monstrosities, but as constitu- 

 ting species of Selache. Mr. T. Gratcombe has observed that, should the mouth of 

 one of these fish be left open, bj inserting a piece of wood between the jaws the 

 peculiar appearance as described by Couch in Polyprosopus is obtained, and of 

 this he has kindly forwarded me two drawings made from this fish when fresh, 

 and which confirm his statement. 



This condition or appearance of the snout has been obseiwed upon by Sir T. 

 Browne, so long ago as 1662, when one was taken entangled in the herring nets, 

 which was particularly remarkable in the vastness of the optic nerves, and three 

 conical hard pillars which supported the extraordinary elevated nose. The seaman 

 named it a scrape. 



Names. — -Basking shark, due to its remaining motionless at the surface of the 

 water, and sun-fish in Ireland for the same reason; sail-fiili because, when swim- 

 ming, its dorsal fin protrudes out of the water like a sail, causing it to be seen from 

 a considerable distance. Hoe mother and homer, signifying " the mother of the 

 Dog-fish" (Low, Orkneys). Heidgi, Welsh. De Reiizenhaal, Dutch. Le Pelerin, 

 French. 



Habits. — It appears to be a quiet, inoffensive fish, which is frequently observed 

 lying motionless on the surface, apparently basking in the sun's rays, some- 

 times even its belly appearing to be uppermost. At certain seasons this 

 unwieldy looking anitnal may be seen leaping out of the water to the height of 

 several feet, and when swimming its dorsal fin is frequently perceived above 

 the surface. In some years it is much more abundant than others. Thus 

 Pennant speaks of the vast shoals which visited the coasts of Wales in the 

 summer of 1756 and a few succeeding years : while the period they are off the 

 coast is about from June to the setting in of cold weather. It is said to migrate 

 regularly from along the west coast of Ireland to the western isles of Scotland. 



Should the April sun be hot, the sun-fish, says Mr. Brabazon, are certain to 

 show above the water, and they remain on the Clew bank, Ireland, until the 

 middle of May. A large shoal of sharks pass annually at this season along the 

 west coast on their way from the southern to the northern seas. They are taken 

 on the sun-fish bank, situated about one hundred miles west of Clew Bay, extending 

 many miles north and south, and a day's sail from the land. They are found on the 

 bank in great numbers, and the large dorsal fin is seen at a great distance, as it 

 rises 3 or 4 feet out of the water while they lie motionless basking in the sun. 



De Kay observes that its large size and habit of swimming near the surface, 

 with its upper jaw projecting out of the water as it moves with open mouth in 

 pursuit of its prey, has suggested to ignorant credulity the idea of some huge 

 aquatic monster which has received the name of " sea-serpent." Possibly its thus 

 swimming near the surface is because the small marine animals, on which it, 

 certainly partially, subsists, are to be found in that situation, and then it strains 

 the water through its gills in order to obtain them. (See p. 303.) 



Low found the stomach of one full of red stuff, like bruised crabs or the roe of 

 the sea urchin, but no fragments of fish. Captain Hadfield, remarking on the 

 Ventnor specimen, says he is inclined to believe that it feeds on seaweeds, though 

 nothing but a glutinous substance, of a yellowish-white colour, was found in its 

 stomach, and the great width of the intestinal canal, 8 inches, he considered 

 tended to prove that it is a vegetable feeder (Zool. 1875, p. 4415). Thompson 

 observes that in Ireland it has been stated that they frequent the herring bays in 

 the fishing season, and not only destroy a good deal of fish, but mar the fishing. 

 The first of these accusations is, however, probably erroneous, but that the mere 

 presence of very large fish does injure fisheries has frequently been asserted. 



Means of capture. — Pennant remarks, they will permit a boat to follow them 

 without accelerating their motion, till it comes almost within contact, when a 

 harpooner strikes his weapon into them, as near to the gills as possible ; but they 

 are often so insensible as not to move till the united strength of two men have 

 forced the harpoon deeper. As soon as they perceive themselves to be wounded, they 

 fling up their tail, plunge headlong to the bottom, and frequently coil the rope 

 round them in their agonies, vainly attempting to disengage the harpoon by 



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