HIKD ON THE MOVEMENTS OF MACKEEEL. 303 



Land, where the spawning grounds on the United States coast south of Cape Cod are alleged to 

 exist, a thin wedge of the Labrador current stretches far into Long Island Sound. 



"In Massachusetts Bay, where a mackerel spawning ground also exists, as also in the vicinity 

 of SteUwagen Bank, the temperature when observed by Dr. Packard in September ranged from 

 41^° to 45°, and the fauna resembled the cold-water species on each side of Jeffrey's Ledge. On 

 George's Shoals the marine life is said by Verrill to be the same as that found in the deeper 

 muddy parts of the G-ulf of Saint Lawrence, and indicates a temperature not above 40°, and prob- 

 ably considerably lower. Bradelle Bank, according to Mr. Whiteaves, presents the phenomenon of 

 a small stony patch tenanted by an assemblage of marine animals which usually inhabits very 

 cold water, and are almost entirely surrounded by another series, which are for the most part 

 prevalent where the bottom is warmer and more affected by surface conditions of temperature. 



"Wherever the areas are situated where young Mackerel are found in the summer we find 

 near at hand a cold-water zone, either existing as a part of the Labrador current at the surface or 

 brought up from greater depths by banks and shoals. On the coast of Prince Edward Island, and 

 in the gulf generally, the cold water lies frequently near the shore, because the diurnal tides mix 

 the strata warmed during the daytime with the cold underlying strata. In the estuary of the 

 Saint Lawrence Dr. Kelly found the surface temperature 57° F. on the 9th July, but three feet 

 below the surface it was 44°, having in that short vertical space sunk 13°; at twenty-four feet it 

 was 40°, or 17° below the surface temperature." 



96. THE CHUB MACKEREL— SCOMBER COLIAS. 



The Chub Mackerel, or, as it is also called, the "Thimble-eye," "Big-eyed Mackerel," of "Bull 

 Mackerel," closely resembles in general appearance the common Mackerel, from which it is distin- 

 guished chiefly by the presence of an air-bladder, and also by the occurrence of a row of indistinct 

 circular spots upon the sides below the lateral line. This is the fish which is called " Spanish 

 Mackerel " in England, and the name was brought to us by the early English fishermen of New 

 England. It has been found at Pensacola and Charleston, as well as in New England. There is 

 another fish closely related if not identical with 8. colias, which Professor Jordan found to be 

 abundant in California, which corresponds to the 8. pneumatophorus of the Mediterranean,^ and 

 has been described from the Pacific as 8. diego. Professor Jordan considers this to be the 8. grex 

 of various authors, but writes that he is not yet prepared to accept as final the judgment of 

 Steindachner and Vaillaut that it is the young of 8. colias. The lower half of its sides is silvery 

 and without any gray spots, such as are conspicuous in 8. colias. Jordan has specimens of the 

 unspotted form much larger than his smallest specimens of the true 8. colias. 



The history of the Chub Mackerel on our coast is a peculiar one. At the beginning of the 

 present century it was exceedingly abundant all along the coast of New England and New York. 

 MitchiU, writing in 1814, remarked of it: 



" Comes occasionally in prodigious numbers to the coast of New York in autumn. This was 

 memorably the case in 1781 and 1813, when the bays, creeks, and coves were literally alive with 

 them, and the markets full of them." 



DeKay remarks: "In the early part of November, 1828, they were also very abundant, and 

 many persons were poisoned by eating them." 



Capt. Epes W. Merchant, of Gloucester, a veteran fishing skipper, who has been familiar 

 with the fisheries of Massachusetts Bay for the past seventy years, told me that the Thimble-eye 



'Cauestrini: Fauna d' Italia. Pesoi, 1873, p. 101. 



