CLASS OF CRUSTACEA. 493 



whose posterior aspect is covered with branchiae ; and it ter- 

 minates with a long styliform. tail. These singular animals 

 inhabit the Indian Ocean and the coasts of America ; they 

 are known by tHe common name of Molucca crabs. 



Fig. 523. Lhnulus, or Molucca Crab. King Crab. 



[" As there is scarcely a subject more interesting in natural 

 history than that part of it which treats of the various meta- 

 morphoses which all animals undergo in their progressive growth 

 from the embryonic to the adult condition, I have ventured to 

 subjoin the observations made on this subject by a former most 

 esteemed student of mine, and a careful observer.* They refer, 

 no doubt, especially to the class cirrhipeds, but mutatis mutandis 

 apply to all. In my late inquiries into the dentition of the 

 salmon, other singular facts have come out, plainly disproving 

 the opinion of M. Valenciennes, that * Naturalists have only to 

 do with the adult forms.' For all these adult forms or species 

 are included in the history of the young, as I have proved with 

 regard to the salmonidae ; whilst all transcendentalists since the 

 time of Goethe and Oken have known that the larva conditions 



* Mr. Henry Goodsir, in the Edinburgh Philosophical Journal. 



