294 



ICHTHYOLOGY. 



lied on at Constantinople on a great or systematic scale, 

 but is chiefly concentrated in the interior of the Mediter- 

 ranean. The species sometimes wanders along the British 

 shores ; and a fine specimen, measuring 9 feet in length, was 

 killed in the beautiful Gairloch, opposite Greenock, in July 

 1831. It is preserved in the Andersonian Museum, Glasgow. 



The fish known to navigators under the name of Bo/iito 

 belongs to our present genus. It is the T/i. pelamj/s of 

 Cuv., and sometimes occurs along the British shores. Re- 

 sembling the Tunny in form, it is a great deal smaller, 

 seldom exceeding the length of 30 inches, and is celebrated 

 in the tropical seas for its eager pursuit of the Flying-fish. 

 The Bonilo of the Mediterranean, however, is the Au.vis 

 vulgaris. 



It is a singular thing, as Cuvier has observed, that a 

 fish so generally met with as the great Lepidopus argy- 

 reus of the European seas, so handsome, and so large. 



Fig. IIL 

 Lepidopus arffijrexis, 



should have remained \mknown to naturalists so recently 

 as the end of the eighteenth century, and that it should 

 have been afterwards successively described by various 

 writers, under a new name, and by each in ignorance of 

 the labours of his predecessor. If we figure to ourselves 

 a large and broad riband of silver, swimming with a wavy 

 motion through the water, and casting from it in its pro- 

 gress the most beautiful reflections of light, we may form 

 some notion of the general aspect of this creature in its 

 living state. Its length, as described by Montagu (under 

 the name of Zipotheca tetradens), was 5 feet 6 inches, with 

 a depth at the gills ot 4^ inches ; it gradually decreased from 

 the vent to the commencement of the anal fin, where it 

 measured onlv 2 inches in depth ; at the end of that fin the 

 form was nearly round, and the diameter only half an inch. 

 The weight, without the intestines, was about six pounds. 

 Montagu's specimen was taken in Salcomb Harbour, on the 

 coast of South Devon, on the 4th June 1808. It was 

 swimming with astonishing velocity, with its head above 

 neater, going, as the fishermen said, "as swift as a bird," 

 and was killed by the blow of an oar. It occurs occasionally 

 on most of the European coasts; is more frequent in some 

 parts of the Mediterranean ; and has been captured as far 

 south as the Cape of Good Hope. 



The very singular form, Neiiticlulii/s scolopacea (Rich.), 

 raptured in the Southern Atlantic by Mr Adams, sur- 

 geon, H.M. ship Samarang, seems to be more nearly allied 

 to Trichiurus than to any other genus, but as its internal 

 structure has not been investigated, its proper position in 

 the system must remain for the present doubtful. It is re- 

 markable, above all other fishes, for the extreme length of 

 its thread-like tail and long jaws, compared to its abbreviated 

 body, many times shorter than the gape of the mouth. It 

 is apodal, with the anus on the thorax, a range of spinous 

 rays, each with a triangular membrane, not connected to the 

 A-i/v-«'<^/ following one, running along the whole back, and a »'efrtral 

 ' equally long, but with taller simple flexible rays, and a more 

 connected membrane. There is no caudal, though, as the 

 tip of the tail was slightly damaged, this tact was not fiilly 



terous 

 Fishes. 



.1/ 



established. When newly caught the fisli had a dull white Classifica- 

 colour, with brown spots. The editor of the Archiven fiir tion — 

 Natm-gescliichte is inclined to place this fish among the Acanthop- 

 Taeniida;, but it seems to us to associate better with Tri- 

 chiurus, and we place it here without inquiring whether 

 Trichiurus be a real Scomberoid or not. 



Naucrates ductor, the famous Pilot-fish of navigators 

 {Gasterosteus ductor, Linn.), so named tiora its habit of 

 keeping company with ships at sea, and frequently swim- 

 ming beneath their bows. It would seem, from early indi- 

 cations of a similar instinct, to be the Poinpilius of the 

 ancients, described as pointing out the way to dubious or 

 embarrassed sailors, and as announcing the vicinity of land 

 by its sudden disappearance. It was thus regarded as a 

 sacred fish. The other story of its serving as a guide to 

 the Shark does not appear to have been transmitted to us 

 from so remote a source. It is not mentioned even by the 

 ichthyologists of the sixteenth century ; and Cuvier regards 

 as the first allusion to it, that of Dutertre in his Description 

 of the Antilles, printed in 1667. Since that period it has 

 been carefully rejieated by all voyagers and compilers ; and 

 Osbeck even makes it a subject of pious reflection on the 

 wonderful ways of Providence. We are told by a greater 

 than Osbeck that " they that go down to the sea in ships, 

 that do business in great waters ; these see the works of 

 tlie Lord, and his wonders in the deep :" but the fact in 

 the present instance seems reducible to this, that the Pilot 

 accompanies both ships and Sharks, sometimes swimming 

 before, sometimes behind, for the sake of preying upon 

 whatever may be thrown overboard in the one case, or lett 

 uneaten in the other. It is true that the Shark never 

 attacks it ; but it is also true that the hawk does not attack 

 the swallow ; and in both instances the reason is the same ; 

 the Pilot being too nimble for the unwieldy Shark in the 

 water, just as the feebler but more agile bird is too swift 

 in its movements for falco in the air. It is thus that the 

 apparent alliance of these dissimilar fishes may be explained 

 even upon general princi|)les, to say nothing of Bosc's 

 observation, who assures us that he has seen hundreds of 

 Pilot-fish, that they always keep at a respectful distance 

 from the Shark, and swim about swiftly in different direc- 

 tions, that they may more certainly avoid it. If any food 

 be thrown overboard, the Pilot stops to seize it, and aban- 

 dons both the Shark and vessel. Geoifroy no doubt tells a 

 story of two Pilot-fish having been seen to take a great deal 

 of trouble, swimming to and fro, in order to conduct a 

 Shark towards a baited hook : but admitting the truth ot 

 the details, it is clear, that whatever advantage might even- 

 tually accrue to tlie conductors, the probable result to the 

 Shark was a cruel death, and one is consequently the more 

 inclined to admire how the narrative itself should find 

 place in a Memoir sur I'affictioii mutuelle des quelques 

 animaux ! The Pilot-fish in question is chiefly a Medi- 

 terranean species, although it also spreads into distant 

 oceans, having been found by Daldorf under the equator. 

 A greta extent of geographical distribution may indeed be 

 expected in reference to a species which is said to suffer 

 itself to be led away immense distances in its eager pursuit 

 of ships. Dutertre records that he saw one which followed 

 his vessel for more than 500 leagues. Whether he kept 

 his eye upon it night and day during all that time, or in 

 w hat other way he ascertained it to be the same individual 

 throughout so long a traverse, is what he does not state, 

 and we therefore cannot explain. 



In further illustration of the subject, we shall subjoin a 

 short extract from a recent publication, Dr Meyen's Reise 

 um die Erde : " The Pilot swims constantly in front of the 

 Shark ; we otn-selves have seen three instances in which the 

 Shark was led by the Pilot. When the Sea-Angel neared 

 the ship, the Pilot swam close to the snout, or near one 

 of the breast fins of the animal ; sometimes he darted 



