238 bulletin: museum of comparative zoology. 



knowledge of subsurface temperatures on the continental shelf at 

 other seasons, and at any season elsewhere than in the region studied 

 by Libbey and Verrill, is limited to a few bottom readings taken by 

 the Fish Hawk (Tanner, 1884a, 1884b), Blake (Smith, 1889) and 

 Albatross (Townsend, 1901). Verrill's observations were located 

 at successive points across the zone between the fifty and 150 fathom 

 contours, and they are especially valuable, because they were taken 

 before and after the extraordinary mortality of the tile fish, Lopholatilus 

 chamaeleotiticeps, of 1882 (p. 266). On July 21, 1880, the Blake ran a 

 line across the continental shelf from Montauk Point, getting the 

 following bottom temperatures: 24 fathoms, 60°; 43 fathoms, 49°; 

 71 fathoms, 51°; 129 fathoms, 51°; and 732 fathoms, 39.5°. Although 

 these readings were taken wdth the Miller-Casella (maximum-mini- 

 mum) thermometer, and hence register merely the coldest water at 

 each station, which may not have been on the bottom, they show that 

 the cold water on the shelf was separated from the even lower tempera- 

 ture of the abyss by a warmer belt at 75-130 fathoms, just as it was in 

 July, 1913; and that this condition obtained as far east as the north- 

 east end of George's Bank, where the bottom temperature, following 

 down the continental slope, rose from 42° at seventy fathoms to 44° 

 at 139 fathoms, and then fell to 40.5° at 300 fathoms. This "warm 

 belt" was certainly distinguishable as late as August 17, 1880, when 

 the Fish Hawk found bottom temperatures of 40°-48° in about 

 thirty fathoms off Block Island. In September and October of the 

 same year, the Fish Hawk took a considerable number of bottom 

 temperatures on the shelf south of Block Island with deep-sea ther- 

 mometers of the reversing type, finding about the same temperature 

 (51°-o3°) at 100-142 fathoms as in July, with colder water deeper 

 down the slope (Verrill, 1880, Tanner, 1884a). But no readings were 

 taken on the inner part of the shelf except in the very shallow water 

 close to shore. The Blake records suggest that the water on the shelf 

 south of Block Island was several degrees warmer, depth for depth, in 

 1880 than in 1913; but the discrepancy may be due to the fact that 

 the observations were taken two weeks later in the former year. 



The Fish Hawk temperatures for 1881 (reversing thermometers), 

 again demonstrate the existence of the "warm belt" bathing the 

 bottom at 70-100 fathoms, with lower bottom temperatures in the 

 shallower water near shore (Verrill, 1881, 1884a, Tanner, 1884b), much 

 the same distribution of temperature as in 1913. Thus on a line 

 S 1/2 W from Marthas Vineyard, the bottom temperature rose from 

 42° at forty -four fathoms to 52° on the bottom between the sixtv- 



