FISH. 159 



CYCLOSTOMI. 



Family.— PETROMYZONID^. 



Myxine australis. Jen. 

 Form. — Scarcely differing from the M. glutinosa, but apparently rather more slender in proportion 

 to its length. Mouth and cirriform appendages the same. Branchial orifices two, very near 

 together, placed beneath, at a little beyond one-fourth of the entire length. A very conspi- 

 cuous row of pores along each side of the abdomen. The tail seems somewhat sharper than 

 in the M. glutinosa, and the rays of the low fin which turns round its extremity rather more 

 distinct. Vent distant from the end of the tail rather less than one-eighth of the entire 

 length. 



Length 1 1 inc. 6 lin. 



Colour. — "Above coloured like an earth-worm, but more leaden; beneath yellowish; head 

 purplish." — D. 



Habitat, Tierra del Fuego. 



Mr. Darwin obtained this species by hook amongst the kelp, in Goree Sound, 

 and other parts of Tierra del Fuego, where he observes it is abundant amongst the 

 rocky islets. Its extreme southern locality would suggest the idea of its being 

 distinct from the 31. glutinosa of the northern seas ; yet the differences between 

 the two, upon comparison, are very slight, and, if it really be so, as I have ven- 

 tured to consider it, it requires an examination of more specimens to lay down its 

 exact specific character. 



Mr. Darwin has made some interesting remarks on the habits of this fish. 

 He observes that it is " very vivacious, and retained its life for a long time ; that 

 it had great powers of twisting itself, and could swim tail first. When irritated, 

 it struck at any object with its teeth ; and by protruding them, in its manner, 

 much resembled an adder striking with its fangs. It vomited up a Sipunculus 

 when caught." He adds, that he " observed a milky fluid transuding through 

 the row of lateral pores." 



