MUSEUM OF COMPARATIVE ZOOLOGY. 15 
our cruise, the temperature at a depth of 2,232 fathoms, somewhat more 
than halfway between Culpepper and Acapulco, falling to 35°.8, the 
temperature being below 36° in the whole of the great basin extending 
between the northerly slope of the Galapagos and the continental slope 
off Acapulco. The surface temperature was 83° off Chatham, it fell to 
81° off James, and varied between 81° and 83° to fall to 81° again 
about half-way to Acapulco, to rise to 84° and fall to 80° off Acapulco. 
The 60° curve rises among some of the Galapagos Islands almost to the 
50 fathom line, but falls rapidly below the 100 fathom line between 
Abingdon and Wenman, retaining that depth nearly to Station 3414 
in 2,232 fathoms (Plate IX.), showing the presence of a large mass of 
warm water flowing eastwardly. From. that point it rises rapidly above 
the 50 fathom line to a short distance off Acapulco, where the water 
close to the shore becomes warmer again. The 45° curve follows nearly 
the line of the 60° curve, reaching for a great part of its length the 
line of 350 fathoms. But the 40° curve shows more markedly than 
the 45° curve the influence of the warmer body of water moving east- 
ward, and again as markedly that of the colder belt close to the Mexican 
mainland. It reaches well below the 600 fathom line for more than 
two thirds its length, extending for a considerable distance to 630, and 
even to 650 fathoms. 
A comparison of the temperature curves of Plates VIII. and IX. will 
show in the one case the large belt of warmer water flowing east in the 
greater part of the oceanic basin extending between the Galapagos and 
Acapulco, and the comparatively colder water flowing north in the oceanic 
valley extending between Cape San Francisco (Galera Point) and the 
Galapagos. 
The few temperatures taken between the different islands of the Ga- 
lapagos are interesting as showing the southern islands, Chatham, Hood, 
and Charles, to be somewhat within the influence of the colder Humboldt 
Current (Plate XI. Figs. 2, 3, 5), while that which sweeps north of 
Chatham across the central islands is somewhat warmer (see Plate X. 
Figs. 1-4), and the upper belt of temperatures is still warmer between 
Abingdon and Wenman Islands (Plate XII.). 
The mixing of the cold and warmer currents flowing between the 
different islands is plainly indicated by the temperature section from 
Indefatigable Island to Bindloe (Plate X. Fig. 2), where the 60° 
curve is at about the 50 fathom line, the 45° at the 300 fathom 
line, and the 40° curve at the 600 fathom line, while between Ab- 
ingdon and Wenman the 60° curve is below the 100 fathom line, the 
VOL. XXIII. — NO. 1, 2 
