CHARACTERISTICS AND DISTRIBUTION OF LAKES 603 
Baikal, is the Dracunculus {Comephorus haicalensis)^ in which the 
head occupies a third of its entire length ; the eyes are uncommonly 
large and protruding ; from the gills to the tail, fins are attached on 
each side. This fish occurs in the deepest parts of the lake ; it is 
said no one ever saw a living specimen. The lake abounds in 
crustaceans and gasteropods. There are four kinds of sponges 
of a dark emerald colour, containing much chlorophyll.^ The seal 
(Phoca haicalensis) is called " nerpa *" by the local inhabitants, and is 
killed during the whole summer. 
Lake Kosso-gol. — One of the tributaries of the Selenga River is 
the Eke-gol, which drains Lake Kosso-gol, in the mountains south- 
west of Irkutsk. This lake is 83 miles long by about 25 miles 
broad, with an area of about 1300 square miles, and lies about 
5470 feet above sea-level. The maximum depth, as shown by 
soundings taken by Peretolchin,^ is 676 feet, the mean depth about 
500 feet. The bottom of the lake-basin is fairly level, and its 
sides steep. In August 1897 the surface temperature was 59° '2 
Fahr. (15°-1 C.) in the northern part of the lake, in August 1899 
54i° Fahr. (12°-5 C.) in the centre (near Dola-Koi Island), and 
in July 1900 46° Fahr. (7°-8 C.) in the south. The temperature 
at 33 feet was 44°'6 Fahr. {T'O C.) in 1897 and 43° Fahr. 
(6-1 C.) in 1900; at 300 feet, about 38^ Fahr. (3^*6 C.) in 1899 
and 1900. In the cold summer of 1902 the surface temperature 
was only 41° Fahr. (5° C.) near Dola-Koi. Kosso-gol belongs to 
ForePs temperate type of lake, i.e. the temperature in summer is 
above that of maximum density, in winter below it. The lake freezes 
at the beginning of December, and becomes free from ice in June or 
July ; the thickness of the ice is from 3 to 5 feet. The air tempera- 
ture is low on the shores, daily means above 55° Fahr. (12°*8 C.) not 
being recorded until the end of July. The transparency of the water 
is very remarkable, the limit of visibility being 80 feet. 
Lakes Tung-ting and Poyang are expansions of the mouths of River Yang-ts 
the two chief southern tributaries of the Yang-tse Kiang. 
Tung-ting Lake, in the province of Hoo-nan, is the largest lake in 
China. It is about 75 miles in length, from 20 to 37 miles in breadth, 
and about 1930 square miles in area, but varies much with the 
seasons. In ancient times it was called the Lake of the Nine Rivers, 
from the fact that nine rivers flowed into it. During winter and 
spring the water is so low that shallow parts become islands ; 
but in summer, owing to the rise in the waters of the Yang-tse 
Kiang, to which it drains, the whole lake-basin is flooded. The 
^ Guide to Great Siberian Railway^ p. 333. 
2 Petermann's Mitt., Bd. 1., p. 152, 1904. 
