Pareioplitie, or Mailed-cheek Fishes 439 



fat and is much valued as food. About San Francisco it is 

 dry and tasteless. 



The Greenlings: Hexagrammidae. The curious family of 

 greenlings, Hexagrammida, is confined to the two shores of the 

 North Pacific. The species vary much in form, but agree in 

 the unarmed cranium and in the presence of but a single nostril 

 on each side, the posterior opening being reduced to a minute 

 pore. The vertebrae are numerous, the scales small, and the 

 coloration often brilliant. The species are carnivorous and 

 usually valued as food. They live in the kelp and about rocks 

 in California and Japan and along the shores of Siberia and 



FIG. 378. Atka-fish, Pleurogrammus monopterygius (Pallas). Atka Island. 



Alaska. The atka-fish (Pleurogrammus monopterygius) is one 

 of the finest of food-fishes. This species reaches a length of 

 eighteen inches. It is yellow in color, banded with black, and 

 the flesh is white and tender, somewhat like that of the Lake 

 whitefish (Coregonus clupeiformis] , and is especially fine when 

 salted. This fish is found about the Aleutian Islands, espe- 

 cially the island of Atka, from which it takes its name. It is 

 commercially known as Atka mackerel. 



In this genus there are numerous lateral lines, and the dorsal 

 fin is continuous. In Hexagrammos, the principal genus of the 

 family, the dorsal is divided into two fins, and there are about 

 five lateral lines on each side. 



Hexagrammos decagrammus is common on the coast of Cali- 

 fornia, where it is known by the incorrect name of rock- trout. 

 It is a well-known food- fish, reaching a length of eighteen inches. 



