196 VERTERRATA. PISCES. 



and by the power of ejecting a copious secretion 

 whenever it considers itself in danger."* 



We have quoted these observations the more 

 readily, and dwelt with the more minuteness on 

 these forms, because the transition from the Ver- 

 tebrated animals to those which are destitute of a 

 skeleton is most important and interesting ; for it 

 must be borne in mind, that the relations we are 

 considering are not those of two allied genera or 

 orders, or even classes, but those which connect 

 two great divisions of the Animal Kingdom, appa- 

 rently separated by a broadly distinct line of demar- 

 cation. 



Amphioxus^ the Lancelot. 



We cannot refrain from noticing this interesting 

 little creature, one of the smallest as well as the 

 lowest of vertebrated animals, of which the only 

 known specimen is in the museum of Mr. Yarrell. 

 It is about an inch and a half in length, trans- 

 parent, pointed at each extremity, without eyes, 

 jaws, or teeth ; having a mouth opening like a line 

 beneath the head, furnished on each side with slen- 

 der filaments. The skeleton is still more rudiment- 

 ary than in the Myxine, being " reduced to a small 

 and slender semi-transparent column, extending 

 throughout and connecting the whole length of the 

 body, like the flexible horny pen in some species 

 of Cephalopods." J 



* Br. Fishes, ii. p. 466. 



t 'A^/f, amphis, both ways, and ot/y, oocus, sharp. Yarrell. 



