Fishes of the Western North Atlantic 173 



Range. Pelagic; in warm temperate and subtropical latitudes; north commonly in 

 the eastern Atlantic to southern Ireland, less regularly to the North Sea and inward as far 

 as the Danish coast and Kattegat; occasionally to the Orkneys and to the Norwegian coast 

 as far north as Lofoten and Trondhjem. Also widespread in the Mediterranean, and 

 recorded from Madeira and Cape of Good Hope. It is known in the west as far north as 

 Nova Scotia and the Gulf of St. Lawrence, south to Brazil and northern Argentina; also, 

 in the eastern Pacific, from Oregon to the Isthmus of Panama and Chile.^® It is also re- 

 ported from the Hawaiian Islands, Fanning Island and "Polynesia," Japan, Korea and 

 China, New Zealand and Australia, and from Ceylon, Arabia and Natal. But whether the 

 Thresher (or Threshers) of the vulpinus group of the western Pacific, New Zealand and 

 the Indian Ocean are identical with vulpinus of the eastern Pacific and Atlantic, or whether 

 more than one species of the group occurs in those regions, is still an open question (p. 

 162). 



Occurrence in the Western Atlantic. The Thresher is reported more frequently and in 

 larger numbers from the offing of southern New England than from anywhere further 

 south along the east coast of the United States. Over the continental shelf off Block Island 

 it has been described as the commonest shark," appearing in May, being most plentiful 

 in June, and remaining until autumn. In the vicinity of Woods Hole, Vineyard Sound 

 and Buzzards Bay, Threshers are taken from time to time in the traps between April 

 and late autumn (see Study Material, p. 168). There is record, in fact, of three fish 

 of 16 feet in one trap in a single morning, and specimens up to 20 feet have been reported 

 locally. Although only two specimens have been recorded in print from Nantucket, 

 Threshers enter the Gulf of Maine in some numbers, at least during some years. Thus, 

 we saw several large ones leaping in Pollock Rip off the southern angle of Cape Cod on 

 August 4, 19 13; it is recorded from Provincetown at the tip of Cape Cod and repeatedly 

 from various localities in Massachusetts Bay {e.g., Boston Harbor, Nahant) as well as 

 from various localities along the coast of Maine, in Passamaquoddy Bay,^* and from the 

 cold waters of the Bay of Fundy (Basin of Minas).^° From time to time Threshers are 

 taken entangled in the nets off the outer coast of Nova Scotia; seemingly they are not 

 rare on the Scotian Fishing Banks and they have even been reported from the Bay of 

 Chaleur in the Gulf of St. Lawrence, this being the most northerly known record for them • 

 on the western side of the Atlantic. 



Being a creature of at least moderately warm waters, it is surprising that the Thresher 

 has been reported more frequently and in larger numbers off southern New England than 



26. Our own comparison of specimens from San Francisco, California, and the west coast of South America (p. 

 168) with a considerable series from Massachusetts fails to reveal any significant differences in proportionate 

 dimensions, shape and relative location of fins, length of tail relative to trunk, size of eye, or in shape and 

 number of teeth. 



17. Nichols and Murphy, Brooklyn Mus. Sci. Bull., 3, 1916: 20. 



28. McKenzie, Proc. N. S. Inst. Sci., 20 (:), 1939: 14. 



29. But the old report of Threshers as common there (Knight, Cat. Fishes N. S., x866: 8) may not have been well 

 founded. 



