ON ZOEA, cy. 7 



&c.) Dr. Leach, with that unconiinon forcsl^iit for which 

 he is distinguished, placed them at the tail of his mala- 

 eostraca,* until having inspected the species discovered by 

 Cranch, he declared them to belong to the podophthalma, 

 and to the same group with Nebalia.f It will no longer 

 be a matter of surprise, that all the leading Naturalists 

 of the present day, should have been at a loss how to dis- 

 pose ofZoea in their arrangements of the Crustacea, when 

 it is known, that this singular type, is not a perfect animal, 

 but merely the larva or imptrfect state of the Crab I and 

 not as had been imagined, an animal sui generis I This 

 is a discovery quite new, and interesting in a double point 

 of view, as proving their real nature, and that the more 

 perfect of the Crustacea undergo a Metamorphosis, and 

 that of a description totally different from any hitherto 

 known ; so little has this been suspected by Naturalists, 

 that as before stated, the contrary has been assigned as 

 one of the distinctive characters of the class, and been used 

 as an argument for their separation from insects. It may 

 be urged, that this is no new discovery, and that Slabber 

 has the merit of having first indicated a metamorphosis in 

 the Crustacea ; the metamorphosis however, which this 

 observer thought he witnessed, is of so different a descrip- 

 tion, that we must either suppose him to have fallen into 

 some error, or that there may be Crustacea which pass 

 through other forms than those now for the first time made 

 known. That Naturalists may be put into possession of 

 all the circumstances necessary to a just decision, we shall 

 first point out the supposed discovery of Slabber, and then 

 state what we have ourselves observed. 



Slabber, wishing to continue his observations on his 

 Zoea, took care to renew the water in which it had been 

 placed, and on the third day, finding its movements become 

 slower, and its colour more pale, he subjected it to the 



* Art. Annulosa, Suppl. Ency. Brit, t Captain Tuckej'a Voyage to the Con^o. 



