FISHES OF THE GULF OF MAINE 323 



The winter home of the spiny dogfish off the American coast has long been a 

 subject of uncertainty, hence it is of interest to record that the schooner Victor found 

 them plentiful about 90 miles southeast of Ambrose Channel Lightship on the tile- 

 fish grounds the middle of January 1928, and that the Albatross II trawled many 

 specimens in February 1931, between Cape Hatteras, N. C, and Cape Henry, Va., 

 in 16 to 70 fathoms of water. It appears probable, therefore, that the continental 

 slope to the southward of New England is the chief wintering ground of this species 

 on this side of the Atlantic. 



Analysis of the sizes and of the stages of development of embryos in females 

 taken at various dates and localities along the coast, and of recent captures of new 

 born dogfish, also adds to our knowledge (previously scanty) of the breeding habits. 



Up until 1925 we had no record of new born dogfish within the Gulf of Maine. 

 This, together with the facts that females containing large embryos had been often 

 taken there in early autumn, that dogfish depart entirely from the gulf over the 

 winter, and that new born young had been reported off Long Island in summer 

 suggested that the area of reproduction of this species is confined to waters west 

 and south from Cape Cod. 



This is not the case, however, for during the past few years, when special watch 

 has been kept for new born dogfish, we have learned of their presence in considerable 

 numbers on Nantucket Shoals and at various localities in the Gulf of Maine from 

 June to August. Evidently, then, the gulf, as well as the waters off southern New 

 England, is an important nursery. The fact that embryos, sometimes with yolk sac 

 nearly absorbed, have repeatedly been found in females off New York in autumn 

 and on the wintering grounds off Virginia and North Carolina in January and Feb- 

 ruary might suggest that the coastal waters of the Middle Atlantic States also so 

 serve. As no new born "dogs" have yet been reported to the southward of New 

 York at any season, this question remains open, however. 



If it should prove that young are born in the southern wintering as well as in 

 the northern summering grounds, the sizes of the embryos, at different localities and 

 dates, would suggest that some are set free as early as January or February; in other 

 words, that the season extends from midwinter right through the spring and summer. 



Greenland shark, Somniosus microcephalus (Bloch and Schneider) 



So seldom is the Greenland shark captured in the Gulf of Maine that it is of 

 interest to record a large one taken off Portland Lightship the summer of 1926, and 

 four others, 4 to 5 feet long, taken in the offing of Portland from 1927 to 1933. A 

 large one was also taken somewhere in the gulf and brought into Gloucester in Jan- 

 uary 1929, and another, about 15 feet long, caught in an otter trawl on Jeffreys 

 Ledge 27 miles northeast of Thatchers Island, off Cape Ann, February 16, 1931. 



KEY TO SKATES AND RAYS 



Experience has shown that existing keys are not adequate for the identification 

 of Gulf of Maine skates and rays. The following revision is therefore offered : 



1. No long dorsal spire on the tail 2 



Tail with long dorsal spines (sting rays) 11 



2. Two small dorsal fins, but no distinct caudal fin (includes all our common skates) 3 



There is a large triangular caudal fin as well as the two dorsals Torpedo 



3. Ventral surface with minute rounded tubercles Raja granulata, 3 



Ventral surface smooth 4 



' Although Raja granulata is not known from the Quit of Maine it can be eipected there as it has been recorded from La Have 

 Bank aDd from the continental edge off Halifax, Nova Scotia, from 200 fathoms. 



