112 



THREE CRUISES OF THE " BLAKE. 



a temperature of over 80 Fahr., which decreases gradually with 

 the depth, till, between 600 and 700 fathoms, it has fallen to 



Fig. o!>5. Ophioconis miliaria. -!f. 



39i. The American continents on one side, and the Antilles 



Fig. .300. OphiomusiuTn planum. 1 ^ 8 . 



on the other, furnish those great land masses the neighborhood 

 of which seems essential to rich and varied marine life. Their 



