446 



SCIENCE. 



[Vol. I., No. 16. 



nets (fig. 3), were used to capture free- 

 swimming animals, whenever the motion of 

 the steamer was sufficiently slow to permit 



Fig. 3. — The towing-net, In the position that it 

 takes while in use, half burled beneath the surface of 

 the water. Those used by us are mostly 10 to 14 

 inches in diameter. 



this mode of collecting. In these towing-nets, 

 and in long-handled dip-nets, we secured a 

 great variet}' of pelagic creatures, such as 

 jell3--fishes, Salpa, Sagitta, various small Crus- 

 tacea, and especially large numbers of Ento- 

 mostraca. 



Our dredgings in this region now cover a belt 

 about 160 miles long, east and west, and about 

 10 to 25 miles wide. The most eastern stations 

 are south-east of Cape Cod ; the most western 

 are south of Long Island. Thej' are mostly 

 between 80 and 110 miles from the eoast-liue of 

 southern New England (see map, p. 444) . The 



regular work of the part}" during the season, 

 Capt. Tanner made a special trip to the Gulf 

 Stream slope, ofl!' Chesapeake Bay, in 1880, 

 and another off Delaware Ba}' in 1881. On 

 both of these occasions valuable collections 

 were made, and additional data in regard 

 to the depth and temperature were obtained. 

 He occupied seven stations, in 18 to 300 fath- 

 oms, in 1880 ; and eight stations, in 104 to 

 435 fathoms, in 1881. These dredgings show 

 the direct southward continuation of the in- 

 shore cold belt, and the warm belt outside of 

 it, as well as the cold deep-water belt, with 

 but little change in the fauna of each. 



2. Physical features of the region. 



The total number of species of animals al- 

 readj^ obtained b}' us from deep water in this 

 area is not less than 800. The number already 

 identified or described, and entered on our 

 lists of the fauna, is about 650. This number 

 includes neither the Foraminifera nor the En- 

 tomostraca, which are numerous, and but few 

 of the sponges. Of this list, less than one- 

 half were known on our coast before 1880, 

 and a large number were entirely unknown 

 to science. Of fishes there are, perhaps, 70 

 species. Of the whole number, already deter- 

 mined, about 265 are MoUusca, includino- 14. 



^\ 



Diagram 1. — To illustrate the relative slojie or profile of the bottom, from the shore to the Gulf Stream 

 slope, and across portions of the slope in several lines. Vertical to horizontal scale, 1: 300. The line h'-o' 

 shows the actual slope along the line n-o. The vertical shading indicates the position of the compara- 

 tively warm water, both of the surface and of the Gulf Stream; oblique shading to the right indicates the 

 cold water of the shallow plateau ; oblique to the left, the cold water of the greater depths. 



depths are mostly between 65 and 700 fathoms. 

 Probably no other equally large part of the 

 ocean basin, in similar depths, has been more 

 fully examined than this. In addition to the 



Cephalopoda ; 90 are Crustacea ; 60, Echino- 

 dermata ; 35, Anthozoa ; and 65, Annelida. 



The apparatus used on the Fish Hawk has 

 been better in manj" respects than most other 



