HISTORY OF FISHES. 



BOOK IV. 



OF CRUSTACEOUS AND TESTACEOUS FISHES. 



CHAP. I. 



THE DIVISION OF SHELL FISH. 



IN describing the inhabitants of the water, a 

 class of animals occur, that mankind, from the 

 place of their residence, have been content to 

 call fish; but that naturalists, from their for- 

 mation, have justly agreed to be unworthy of 

 the name. Indeed the affinity many of this 

 kind bear to the insect tribe, may very well 

 plead for the historian who ranks them rather 

 as insects. However, the common language 

 of a country must not be slightly invaded ; the 

 names of things may remain, if the philoso- 

 pher be careful to give precision to our ideas 

 of them. 



There are two classes of animals, therefore, 

 inhabiting the water, which commonly re- 

 ceive the name of fishes, entirely different from 

 those we have been describing, and also very 

 distinct from each other. These are divided 

 by naturalists into Crustaceous and Testaceous 

 Animals; both, totally unlike fishes to ap- 

 pearance, seem to invert the order of nature ; 

 and as those have their bones on the inside, 

 and their muscles hung upon them for the 

 purposes of life and motion, these, on the con- 

 trary, have all their bony parts on the outside, 

 and all their muscles within. Not to talk 

 mysteriously all who have seen a lobster or 

 an oyster, perceive that the shell in these 

 bears a strong analogy to the bones of other 

 animals ; and that, by these shells, the ani- 

 mal is sustained and defended. 



Crustaceous fish, such as the crab and the 

 lobster, have a shell not quite of a stony hard- 

 ness, but rather resembling a firm crust, and 

 in some measure capable of yielding. Testa- 

 ceous fishes, such as the oyster or cockle, are 

 furnished with a shell of a stony hardness ; 

 very brittle, and incapable of yielding. Oi" 



the crustaceous kinds are the Lobster, the 

 Crab, and the Tortoise : of the testaceous, that 

 numerous tribe of Oysters, Mussels, Cockles, 

 and Sea-Snails, which offer with infinite va- 

 riety. 



The crustaceous tribe 1 seems to hold the 

 middle rank between fishes, properly so called, 

 and those snail-like animals that receive the 

 name of testaceous fishes. Their muscles are 

 strong and firm, as in the former; their shell 

 is self-produced, as among the latter. They 

 have motion, and hunt for food with great avi- 

 dity, like the former. They are incapable of 

 swimming, but creep along the bottom, like 

 the latter: in short, they form the link that 

 unites these two classes, that seem so very op. 

 posite in their natures. 



Of testaceous fishes we will speak hereafter. 

 As to animals of the crustaceous kind, they 

 are very numerous, their figure offers a hun- 

 dred varieties : but as to their nature, they are 

 obviously divided into two very distinct kinds, 

 differing in their habits and their conforma- 

 tion. The chief of one kind is the Lobster; 

 the chief of the other, the Tortoise. Under 

 the Lobster we rank the Prawn, the Cray-fish, 

 the Shrimp, the Sea-Crab, the Land-Crab, 

 and all their varieties. Under the Sea-Tor- 

 toise, the Turtle, the Hawksbill-Turtle, the 

 Land-Tortoise, and their numerous varieties. 



CHAP. II. 



CRUSTACEOUS ANIMALS OF THE LOBSTER 

 KIND. 



HOWEVER different in figure the lobster and 

 the crab may seem, their manners and con- 



1 All the animals of this class are covered with inte- 



