188 FISHES OF MASSACHUSETTS. 



fishing, for the oil they furnish ; and it is said to be quite a 

 valuable business. The fishes themselves are dried for food 

 for the cattle, and their skin is considerably used for polishing 

 by the mechanic. They average about eight or ten pounds 

 weight ; sometimes they weigh fifteen pounds. They are 

 readily caught with the hook. These shoals seldom remain 

 in shallow water, or near the shore, more than three or four 

 days ; they feed upon the off'al and garbage thrown upon the 

 bottoms by the fishermen, and so perfectly do they clean the 

 ground, that it is observed by old fishermen, that when the 

 spring shoal of dog-fish has been unusually large, the cod fish 

 are found in much larger numbers upon the same localities 

 afterwards. In Scotland, the flesh of this fish is much eaten 

 by the lower classes, and the refuse portions afl'ord a valuable 

 manure. 



A fine specimen before me, thirty-four inches in length, pre- 

 sents the following appearances : All the upper part of the 

 body of a slate color, which is deeper upon the head ; lighter 

 below the lateral line ; beneath, white ; just under the lateral 

 line, a row of circular white spots ; a few similar spots irregu- 

 larly distributed upon the back. Length of the head to the 

 whole length of the fish, nearly as 4 to 9 ; the head flattened 

 above, tapering to a blunted snout. Eyes horizontally elongated ; 

 their longest diameter nearly equal to one fourth the length of 

 the head ; pupils small, black ; irides silvery, with a cupreous 

 tint. Orbit large, allowing great motion to the eye. The dis- 

 tance between the eyes equal to more than half the length of 

 the head. Between the eyes, two longitudinal patches of nu- 

 merous mucous glands, which are indistinctly continued nearly 

 to the extremity of the snout. Temporal orifices back of the 

 eye, and just above the line of the eye ; their length is equal 

 to the short diameter of the eye. All the lower portion of the 

 head in front of the mouth sprinkled over with mucous orifices, 

 which, like those between the eyes, exude, when pressed, a 

 gelatinous secretion. Nostrils double. Mouth large ; when 

 expanded, nearly circular. In the upper jaw, three rows of 

 teeth ; in the lower jaw, two rows ; these teeth have very sharp 



