PHOSPHORESCENT SCOPELOIDS. 483 



entirely naked ; barbels are wanting ; and the fatty fin is either rudimental or of 

 very minute size. Both the premaxillse and maxillae take a share in the formation 

 of the margin of the upper jaw, and bear pointed teeth of variable length. The 

 bones of the gill-cover are not fully developed ; the gill-opening is of great width ; 

 false gills may or may not be developed; and, when present, the air-bladder is of 

 simple structure. The ovaries are furnished with ducts. Whereas in the figured 

 species the teeth are small, in the allied genus Chauliodus they are greatly 

 elongated, and thus indicate highly predaceous habits on the part of their owner. 

 Hedgehog- The members of the second family, of which the bearded 



Mouths. hedgehog-mouth (Echiostoma barbatum), shown in the lower figure 

 of our illustration, is taken as an example, may be readily distinguished from the 



SILVERY LIGHT-FISH, AND BARBED HEDGEHOG-MOUTH (h liat. size). 



preceding by the presence of a long barbel to the hyoid : the skin being either 

 naked or covered with exceedingly delicate scales, and the fatty tin (as in the 

 figured specimen) frequently wanting. In other characters these fishes closely 

 resemble those of the preceding family. When a fatty fin is present, as in the 

 genus Astronesthes, the rayed dorsal is of considerable length, and placed in 

 advance of the anal; but in the other genera both the anal and dorsal are short, and 

 placed opposite to one another a short distance in advance of the forked caudal. 

 In the genus represented by the figured species, the body is naked and the pectoral 

 fins are filamentous ; but in the allied Stomias there are exceedingly small scales 

 which scarcely overlap one another. Occasionally met with floating in a helpless 

 condition, these fishes have been dredged from depths of eighteen hundred fathoms; 

 and it will not escape the notice of the reader that, although dwelling in total 

 darkness, they, like most of their allies, have well-developed eyes. On this point, 



