198 



ON ZOOLOGICAL SYSTEMS, AND THE 



its prey This species, 1. piscatorius, which is about seven feet long, anti 

 inhabits most European seas, hirks behind sand-hills or heaps of stone, 

 and throwing over them the slender appendages on his head, which have 

 the appearance of worms, entices the smaller fishes to advance and play 

 around them till they come within his reach, when he instantly darts for- 

 ward and secures them as his spoil. 



The SIXTH and last okder of fishes is denominated chondroptery- 

 Gious, as hav^ing the gills wholly cartilaginous, which constitutes its ordinal 

 character. It includes, among other kinds, the acipenser or sturgeon, 

 squalus or shark, raia or ray, petromyzonor lamprey, and gastrobranchus 

 or hag-fish. Of these one of the most useful is the sturgeon : its differ- 

 ent species may be ranked among the large fishes ; they are inhabitants 

 of the sea, but ascend rivers annually. The flesh of all of them is most 

 delicious ; from the roe is procured the sauce called caviare, and from the 

 sounds and muscular parts is made isinglass. They feed on worms and 

 other fishes, and the females are larger than the males. 



This order, in the shark, contains the most dreadful of all the monsters 

 of the main. The squalus Carcharias^ or white shark, which often extends 

 to thirty feet in length, and four thousand pounds in weight, follows ships 

 with a view of devouring every thing that comes in his way, and has occa- 

 sionally been known to swallow a man whole at a mouthful. But in order 

 to guard us in some degree against the perils of their presence, a peculiar 

 stream of light issues in the dark from their tapering subcompressed bodies, 

 which cannot well be mistaken ; and as some compensation for their ra- 

 pacity, we obtain from their liver a large quantity of useful oil, and find 

 in their skin a very valuable material for carriage-traces in some countries, 

 and for polishing wood, ivory, and other hard substances, in all countries. 



The next class to that of fishes in an ascending direction is named am- 

 phibia ; which, for the sake of brevity, and having no English synonym 

 to meet it, I shall take leave now, as I have on former occasions, to render 

 AMPHiBiALs. The term, indeed, whether regarded as Greek or English, 

 is not very strictly precise in its present application ; for it intimates an 

 intention to include in this class all animals capable of existing in the two 

 elements of air and Vt^ater. We have already observed, however, that 

 there are various fishes, as the eel-tribe generally, one species of the perch, 

 and two or three of the exocoetus or flying-fish, to wliich many more might 

 be added that are capable of existing in air as well as in v/ater ; while 

 the insect kinds offer us a still greater number that are similarly endowed, 

 and the worms a still more numerous train, it has been said, indeed, that 

 the animals of this class have a peculiar agreement in the structure of 

 their organs of respiration, which makes an approach to that of birds and 

 quadrupeds, and dilTers very essentially from that of fishes, insects and 

 worms. Upon the whole, however, there is no class that offers so great 

 a diversity in the make of its respiratory organs as the class before us, of 

 which I had occasion to take notice in the progress of our last series 

 of study In the tortoise and others among the more perfect of the am- 

 phibious tribes, the remark of their approximation to the respiratory organs 

 of the higher classes will unquestionably hold ; but it will by no means 

 hold in various cases of the lizards ; while the proper place for the siren, 

 which is possessed of both lungs and gills, remains doubtful to this mo- 

 ment : it is sometimes grouped among the fishes, sometimes in the order 

 of amphibious reptiles ; while Linneus, after having in the earlier editions 

 of his system fixed it in this last situation, appears to have intended, had 

 his fife been spared long enough, to have forraed a new order of amphi- 



