illustrating the Distribution of Marine Animals. 203 



(same latitude with the extremity of the peninsula of Cali- 

 fornia), 115° west, a temperature of 69-41° F. The line of 

 68° will pass from the extremity of this peninsula the tem- 

 perature of the coast below, as it is shut off mostly from the 

 more northern or cold waters, being much warmer. The 

 temperature 69*41°, in the middle of December, is probably 

 two and a half degrees above the cold of the coldest month, 

 judging from the relative temperature of the latter half of 

 December and the month of February at San Bias. Leaving 

 California, the isocryme of 6&° will therefore bend a little 

 southerly to 22J°, in longitude 115° west. In 23° 56' north, 

 128° 33' west, Beechey, on January 11, found the temperature 

 of the sea 67*83° F. The line of 68° passes north of the 

 Sandwich Islands. The mean temperature of the sea at 

 Oahu, in February 1827, was 69*69° F. 



Near China this isocryme is bent far south. At Macao, 

 in winter, Vaillant found the sea-temperature, on January 

 4, 59° F. ; on January 5 to 10, 52*7° to 50° F. ; January 11 and 

 12, 49*87° to 48*74° F. ; January 13 to 16, 50*9° to 52-16° F. ; 

 and at Touranne in Cochin China, on February 6 to 24, the 

 sea-temperature was 68° to 68^° F. ; in 16° 22' north, 108° 

 11' east, on January 24, it was 67°; in 12° 16' north, 109° 

 28' east, it was 74-12° F. The very low Macao temperature 

 is that of the surface of the bay itself, due to the cold of the 

 land, and not probably, as the other observations shew, of 

 the sea outside. 



The line, before passing south, bends northward to the 

 south-east shore of Niphon, which is far warmer than the 

 south-east coast, along Kiusiu. In the Report of the Morri- 

 son's visit to Jeddo (Chinese Repository for 1837), a coral 

 bottom is spoken of, as having been encountered in the har- 

 bour of Jeddo. According to Sieboldt (Crust, Faun. Japon., p. 

 ix.), the mean winter temperature (air) of Jeddo is 57° F. ; 

 while that of Nagasaki, although farther south, is 44° F. 



Isocryme of 62° F. — On January 8, 1827, Beechey found 

 in 29° 42' north, 126° 37' west, the temperature 62*75° F. ; 

 while on the preceding day, 32° 42' north, 125° 43' west, the 

 sea- temperature was 60*5° F. Again, on December 11, in 

 29° north, 120° west, the temperature was 62*58° F. 



