DIVISION II. 



VI— OX THE ANATOMY OF AMPHIOXUS 

 LANCEOLATTJS.*— Plate I. II. 



The genus Amphioosus was instituted by Mr. Yarrell for the 

 reception of a singular little animal which he received from Mr. 

 Couch. The characters of this genus, as given in the History 

 of British Fishes,~j* are, " body compressed, the surface without 

 scales, both ends pointed, a single dorsal fin extending the 

 whole length of the back; no pectoral, ventral, anal, or 

 caudal fins ; mouth on the under part of the head, narrow, 

 elongated, each lateral margin furnished with a row of slender 

 filaments." 



My attention was particularly directed to Mr. Yarrell's 

 description of the Lancelet, by an announcement by my friend 

 Mr. Forbes, at the Newcastle Meeting of the British Associa- 

 tion, of the capture of two specimens on the Manx coast. 

 With his characteristic liberality, that gentleman has put these 

 two specimens into my hands, with a recpiest that I would 

 employ them for the purpose of drawing up a detailed account 

 of tlic animal 



Unwilling to mutilate both, I have confined my dissections 



to <ine of the indi\ Lduals, and have been fortunate enough to 



i its leading anatomical peculiarities, to verify most of 



the observations of the anatomists who have preceded me in 



id before the Royal Society of Edinburgh Maj ", I s II. 

 i YarrelTs History q) British Fishes, vol. ii i" ;i 16 . 



