66 



nessed the result of their ravages until this summer, when, on a 

 visit to Monterey, where it is especially abundant, he was shown 

 by Professor Jordan several rock cod which had been literally 

 eaten alive by them, and had washed ashore mere shells. The 

 hag enters by the gills, or occasionally by devouring the eye, and 

 eats its way into the flesh of its victim, consuming it until it dies 

 of weakness, but presumably leaving, like the ichneumons that 

 prey upon butterfly caterpillars, the vital parts untouched till last. 

 Shells of fishes thus eaten are frequently found in Monterey Bay, 

 and are usually quite fresh, as if but just dead. The hag is fitted 

 for its work by its suctorial mouth, terminal, soft, unprovided with 

 jaws, and forming a round opening when in use, as well as by 

 two rows of teeth on each side of the gullet. The mouth is sur- 

 rounded by barbels, and in preserved examples is scarcely visible. 

 The aspect of the hag, the lowest of vertebrates except the lancelet 

 (if the latter has any right to be called a vertebrate), is strongly sug- 

 gestive of a relationship between worms and vertebrates, and the 

 observer can scarcely maintain the superiority of such a creature as 

 this over beings organized as intricately as insects and Crustacea. In 

 form it is wormlike. There is no fin above or below to break the 

 continuous round body, and the barbels suggest a worm, rather than 

 a vertebrate; yet a vertebrate it undoubtedly is, having the nervous 

 system and backbone of a vertebrate, although the former is of low 

 order, and the latter is but a cartilaginous rod, with a rudimentary'' 

 cranial expansion at its anterior extremity. 



This species, which is widely spread, was first noticed as Californian 

 by myself, and was described as new, under the name of Bdellostoma 

 stouti, from an example taken in Eel River, Humboldt County, 

 California — a river which derives its name not from the presence of 

 eels, but of lampreys and hags, both of which are sold for food as 

 eels. The number of gill openings is not — at least in some examples — 

 equal on both sides, but is twelve on one side and eleven on the 

 other. 



The fishermen of Monterey declare that one of these parasitic fishes 

 will devour a fish of six to eight pounds weight in a single night. It 

 is especially destructive to fish taken in gill-nets. When the hulk 

 is taken out of the net, the hag scrambles out with great alacrity. 

 It reaches a length of fourteen inches, and is not used for food at 

 Monterey. 



