LAMPKEYS. 



695 



in the abdominal cavity of other fishes, especially Gadoids, 

 into which they penetrate to feed on their flesh. They secrete 

 a thick glutinous slime in incredible quantities, and are 

 therefore considered by fishermen a great nuisance, seriously 

 damaging the fisheries and interfering "with the fishing in 

 localities where they abound. Myxine descends to a depth 

 of 345 fathoms, and is generally met with in the Norwegian 

 Fjords at 70 fathoms, sometimes in great abundance. 



Myxine. — One external branchial aperture only on each side 

 of the abdomen, leading by six ducts to six branchial sacs. 



Three species from the North Atlantic, Japan, and Magel- 

 hgen's Straits. 



Pig. 320. — Myxine australis. A, Lower aspect of head ; a, Nasal apertui-e ; 

 6, Mouth ; g, Branchial aperture ; c, Vent. 



Bdellostoma. — Six or more external branchial apertures on 

 each side, each leading by a separate duct to a branchial sac. 

 Two species from the South Pacific. 



