SECTION VL 



27 



A fecond obfervation I fhall make is, 

 that the moft general ftru£lure of tefta- 

 ceous animals is to be attached to their 

 Shells, and to be always fixed in them by 

 one or more ligaments or mufcles. This 

 fixation certainly aiifvvers to reafon ; for 

 thefe creatures can never probably be ima- 

 gined to form their Shells, and augment 

 them when neceffary, had not the animal 

 itfelf a fixed and common communication 

 with its Shell, by means of mufcles, to 

 tranfmit the proper juices for the increafe 

 of it. Yet, however, it is averred, that 

 the fifh of three families are not always 

 affixed by mufcles to their Shells, and thofe 

 are the Vermiculi, the Dentalia, and the 

 Paper Nautili. 



The Paper Nautilus appears not to be 

 fixed by any one part to its Shell, and is 

 very frequently feen without it. The fiflier- 

 men muft be very nimble to catch the fifh 

 in its fheli, they quit their Shells with fuch 



eafe. 



