120 THREE CRUISES OF THE “BLAKE.” 
the warm waters of the Gulf Stream. The belt is quite 
narrow at Cape Hatteras, owing to the steepness of the conti- 
nental slope at that point, and gradually increases in width 
and depth as we go south along the trough of the Gulf 
Stream, its greatest width being off the Carolina and Georgia 
coasts. The marked influence of the currents on the fauna 
of the district through which they flow is well illustrated by 
the wholesale destruction of the tile fish and of several species 
of crustacea during the winter of 1881-82, as noted by Pro- 
fessor Verrill, of the United States Fish Commission. This 
was perhaps due, as he suggests, to the fact that a severe 
storm forced the cold water of the shallow shore-belt out to sea, 
and suddenly lowered the temperature of the narrow belt of 
outlying warm water. This belt covers an area which is prob- 
ably the northern limit of many species collected in abundance 
during previous seasons. 
We were greatly surprised at the meagreness of the fauna on 
the lines off Charleston and in the Gulf Stream. Owing partly 
to the very gradual slope of the continent towards deep water, 
and partly to the strong current of the Gulf Stream, which sweeps 
everything off the bottom along its course, there is but little 
food for the deep-water animals, and it was only along the edges 
of the Gulf Stream where mud and silt had accumulated that 
we made satisfactory hauls ón our southern lines. What was 
obtained seemed to be a scanty northern extension of the fauna 
of the Caribbean Sea and of the Gulf of Mexico occurring 
between the hundred and the three-hundred-and-fifty fathom 
lines. It was not until we trawled on the steep slope of the 
Gulf Stream plateau south of Cape Hatteras, where the bottom 
was fine mud and globigerina ooze, that we made a rich harvest 
again, in striking contrast to the poor hauls along the well- 
swept rocky or hard bottom of the Gulf Stream to the south- 
ward. Although pteropods were very common at the surface 
all the way from Charleston to Cape Hatteras, they were only 
rarely brought up dead from the bottom; but when the steep 
slope south of Hatteras was reached, they again assumed a 
prominent part in the composition of the bottom mud. 
The effect of currents on the distribution of birds has been 
