214 BULLETIN OF THE BUREAU OE FISHERIES. 



Table 2. — Distribution of Summer Heat Income to Thermal Regions oe Lakes. 



[NoIE.— Mean is derived from mean temperatures. Extent = vertical thickness of region in meters; R. T. = reduced thickness 

 of region, i. e.. the thickness in meters of the region when reduced to the area of the surface of the lake. It is computed by 

 dividing the volume of the stratum expressed in meters by the area of the surface of the lake expressed in square meters; 

 T— gain of heat above 4.0°. i. e., the summer heat income expressed in degrees centigrade; Cal.^gram calories per square 

 centimeter of lake surface; P. ct. =per cent.] 



CANANDAIGUA LAKE. 



CAYUGA LAKE. 



