illustrating the Distribution of Marine Animals. 205 



the temperature was 69*8° F, ; and the next day, in 1° 25' 

 south, 84° 12' west, it was 70° F. ; on the 17th, 1° south, 87 

 42' west, it was 71*28° F. ; and on the 14th, nearer the shore 

 of Guayaquil, in 3° 18' south, 80° 28' west, it was 78° F. 

 Again, at Payta, one hundred miles south of Guayaquil, in 

 5° south, the sea-temperature was found by Vaillant, July 

 26 to 31, to be 608° to 61*° F. The isocryme of 71° F. 

 consequently leaves the coast just north of the bay of Guaya- 

 quil, while those of 68° and 62° F. both commence between 

 Guayaquil and Payta. Payta is situated so far out on the 

 western cape of South America that it receives the cold 

 waters of the south, while Guayaquil is beyond Cape Blanco, 

 and protected by it from a southern current. At the Galla- 

 pagos, Fitzroy found the temperature as low as 58^° F. on 

 the 29th of September, and the mean for the day was 62°. 

 The average for' September was, however, nearer 66°. The 

 Gallapagos appear, therefore, to lie in the Warm Temperate 

 Region, between the isocrymes of 62° and 68° F. Fitzroy, 

 in going from Callao' to the Gallapagos, early in September, 

 left a sea-temperature of 57° F. at Callao, passed 62° F. in 

 9° 58' north, and 79° 42' west, and on the 15th, found 68^° 

 F. off Barrington Island, one of the Gallapagos. 



In the warm season the cold waters about the Gallapagos 

 have narrow limits ; Beechey found a sea-temperature of 

 83-58° on the 30th of March 1827, just south of the equator, 

 in 100° west. But in October, Fitzroy, going westward and 

 southward from the Gallapagos, found a sea-temperature of 

 66° F. at the same place ; and in nearly a straight course 

 from this point to 10° south, 120° west, found the sea-tem- 

 peratures successively 68°, 70°, 70*° 72^°, 73*°, 74° ; and be- 

 yond this, 75i°, 76^°, 77^° F., the last on November 8, in 

 14° 24' south, 136° 51' west. These observations give a wide 

 sweep to the cold waters of the colder seasons, and throw 

 the isocrymes of 74° and 68° F. far west of the Gallapagos. 

 Captain Wilkes, in passing directly west from Callao, found 

 a temperature of 68° F. in longitude 85° west ; 70° F. in 

 95° west ; and 74° F. in 102° to 108° west. These and other 

 observations lead to the positions of the isocrymes of 74°, 

 68°, and 62°, given on the chart. The line of 74° passes 



VOL. LVI. NO. CXII. — APRIL 1854. P 



