UTILIZATION OF DOGFISH 133 



Characteristics: Besides the spines on the pectorals, head, back, land tail common 

 to most species, this species is marked by the presence of large spinous plates or 

 bucklers; these are large, strong spines, with broid, stellate or shield-like bases 

 arranged as follows: one or two in front of each eye; one on each side between the 

 eye and the spirafcle; a pair on the shoulder, the smaller in front; and fourteen or 

 more forming a dorsal row, beginning just back of the head and extending to the 

 caudal; an irregular row of spines on each side of the tail, separated from the 

 membrane by a band of shagreen; males with two or more rows of claw-like spines 

 on the pectorals. Length IJ to 2 feet.* 



"This skate or ray is usually called the Starry Ray and it is the most common 

 species taken on the local cod trawls. I have seen several dozens taken in about three 

 hours by one dory" (at Canso).^° 



This species occurs frequently at St. Andrews, IT.B. 



APPENDIX A. 

 REPORT ON ANALYSES OF CANNED GRAYFISH (DOGFISH) (2i). 

 By Dr. Emil J. Baumann, 

 Department of Biochemistry, University of Toronto. 



The cartilaginous bones were removed from the muscle and the entire contents of 

 the can (meat and liquor) were put through a hashing machine two or three times. 

 A more or less pasty mass resulted, which was carefully mixed, and a portion con- 

 taining 300 grams was taken for analysis. These were heated on a water bath for 

 one half-hour, with three or four times their weight in water. (Made acid with 1 cc. 50 

 per cent acetic acid) with occasional shaking. The liquid was decanted through 

 cheesecloth. The muscle was again comminuted and re-extracted with hot acidulated 

 water, as above, four times, making five extractions in all. The combined extracts were 

 filtered through a paper pulp filter. This was a slow and tedious process, but resulted 

 in a clear opalescent filtrate. 



The extracts were then concentrated under diminished pressure in a water bath, 

 the temperature of the water in the bath never rising above 55° C. When the extracts 

 had been reduced from 150 to 100 cc, 5 volumes of 90 per cent alcohol were added to 

 precipitate any remaining protein. A little glycogen was probably precipitated also. 

 After standing overnight the alcohol solution was filtered and the precipitate care- 

 fully washed with 75 per cent alcohol. The solution at this stage was distinctly acid. 

 The alcohol filtrate was evaporated under diminishing pressure to about 75 or 100 cc, 

 about 100 cc. of water added and concentration repeated to remove the last traces of 

 alcohol. (Alcohol sometimes interferes with amino nitrogen determination.) 



The concentrated extract was washed from the distilling flask and made up to a 

 volume of 250 cc. Urea determination was made on 1 cc, aliquots (measured with a 

 calibrated Ostwald pipette) by the Urease method of Van Slyke and CuUen, Jour, of 

 Biol. Chem., Vol. 24, p. 17, 1916. 



Ammonia was determined by the usual aeration method of Eolin, on a 1 cc, 

 aliquot. 



20 Cornish, 19 07. 



21 The cans of grayfish used for these analyses were put up by the Gorton-Pew Com- 

 pany of Boston. The Blue Label samples were obtained by the writer from the factory 

 about June 30, 1917, were taken to St. Andrews and forwarded from there to Dr. Baumann 

 in Toronto. The cans were understood to be put up in April or May of the same year. The 

 Red Label samples were obtained directly from the Gorton-Pew Company by Dr. Baumann 

 in July, 1917. The analyses were made in the latter part of July, 1917. 



In a letter. Dr. Baumann remarks: "The material I received from the factory (Red 

 Labels) was better looking, whiter and meat more firm." 



