Opisthomi and Anacanthini 539 



is used instead of glass for windows. In Alaska, according to 

 Dr. Ball, it reaches a length of six feet and a weight of sixty 

 oounds. 



FIG. 490. Burbot, Lota maculosa (Le Sueur). New York. ' 



The rocklings (Gaidropsarus and Enchelyopus} have the 

 first dorsal composed of a band of fringes preceded by a single 

 ray. The species are small and slender, abounding chiefly in the 

 Mediterranean and the North Atlantic. The young have been 



FIG. 491. Four-bearded Rockling, Enchelyopus cimbrius (Linnaeus). 

 Nahant, Mass. 



called "mackerel-midges." Our commonest species is Enchely- 

 opus cimbrius, found also in Great Britain. 



The cusk, or torsk, Brosme brosme, has a single dorsal fin 

 only. It is a large fish found on both shores of the North Atlan- 

 tic, but rather rare on our coasts. 



Fossil codfishes are not numerous. Fragments thought to 

 belong to this family are found in English Eocene rocks. 



Nemopteryx troscheli, from the Oligocene of Glarus, has three 

 dorsal fins and a lunate caudal fin. Other forms have been 

 referred with more or less doubt to Gadus, Brosmius, Strinsia, 

 and Melanogrammus. 



Gill separates the "three-forked hake" (Raniceps trifur- 

 cus) of northern Europe as a distinct family, Ranicipitida. In 

 this species the head is very large, broad and depressed, differ- 

 ing in this regard from the codlings and hakes, which have also 



