242 bulletin: museum of comparative zoology. 



from his profiles, 1890 seems to have been intermediate between 

 1889 and 1913. 



Libbey continued his survey of subsurface temperatures in subse- 

 quent years; but the results have never been published, nor, except 

 in a few instances, have the various bottom temperatures taken by 

 the vessels of the U. S. Bureau of Fisheries on collecting trips south of 

 Marthas Vineyard. Hence it is not possible to draw any comparison 

 between 1913 and any year since 1890. 



There are no records of subsurface temperatures for winter, or 

 spring, except in the water close to the coast, e. g. at Woods Hole. 



The temperatures taken in the Gulf of Maine by Verrill are summa- 

 rized elsewhere (1914a) ; but the records obtained by the Speedwell 

 (Smith, 1887), the Fish Hawk (Verrill, 1882, 1884a, Tanner, 1886) and 

 by Dawson, (1905), were omitted there. The Speedwell took bottom 

 and serial temperatures in various parts of the Gulf in the summers of 

 1877, 1878, and 1879; but those of 1877 are of little value, because 

 taken with Miller-Casella thermometers, two instruments often differ- 

 ing by as much as 6° when used simultaneously at the same depth. 

 In 1878 and 1879, however, the Negretti and Zambra reversing ther- 

 mometers were employed. Sixteen serial temperatures, in July, 

 August, and September, 1878, in depths greater than twenty-five fath- 

 oms, show that the water was slightly colder below about forty-five 

 fathoms at the mouth of Massachusetts Bay, and off Cape Ann, than 

 in 1913, and less uniform vertically; with bottom temperatures of 

 38.5° to 41.2°, instead of about 40.3° as in 1912; 41°or more asin 1913. 

 And the bottom water of the western basin was 38.5°-39°, as late as 

 August 31 in 1878. But in August the surface layers were decidedly 

 warmer in 1878 than in either 1912 or 1913, as illustrated by the 

 following serial temperatures in Massachusetts Bay. 



