NORTHWESTERN LAKES OF THE UNITED STATES. 
105 
LAKE WHATCOM, WASH. 
Lake Whatcom is one of the deeper lakes, with a thermocline between 16 and 
19 m. The ma xim um number of Crustacea per cubic meter of water was found in 
the 0-10 m. stratum. About one-third of Cyclops bicuspidatus, which comprised 
fully one-half of the Crustacea, and 86 per cent of Epischura nevadensis, which com- 
prised almost one- third of the Crustacea, were in this stratum. Cyclops was the 
only crustacean found below 30 m. 
The maximum number of nauplii per cubic meter of water was found between 
15 and 20 m. A large number of nauplii was found in the 20-30 m. stratum, but 
there was a rapid decrease in numbers below 30 m. 
Rotifers were found in greatest abundance between 5 and 10 m. Polyarthra 
platyptera was the predominant rotifier and was found at all depths. All of the 
Conochilus were between 5 and 15 m. Noiholca longispina was most abundant in 
the 10-20 m. stratum. 
The maximum number of algae per cubic meter of water, consisting of Micro- 
cystis and Aphanocapsa, was in the 0-5 stratum. Only a comparatively few 
algae were found below the thermocline. Asterionella was the only diatom found 
above and Cyclotella the only one found below the thermocline. No diatoms were 
found below 20 m. 
LAKE WILDWOOD, WASH. 
The Crustacea were most abundant above the thermocline, especially between 
3 and 6 m. Diaptomus oregonensis was confined to the upper 6 m. Cyclops bicuspi- 
datus, which composed 70 per cent of the Crustacea, was found at all depths. The 
lack of free oxygen below 20 m. may account for the rise in the number of Crustacea 
in the 12-17 m. stratum. (See Table 12, p. 135.) - 
The nauplii were well distributed throughout the lake, with the maximum 
number per cubic meter of water between 6 and 9 m. Fully one-third of the nauplii 
were in this stratum. 
The major portion of the Rotifera in Lake Wildwood was below the thermo- 
cline, with the largest number per cubic meter of water between 9 and 12 m. Over 
one-third were Triarthra, and almost one-half were Polyarthra platyptera. All of 
the Conochilus were above 6 m. 
Ceratium was most abundant in the 3-6 m. stratum. A few Dinobryon were 
found in the 0-3 m. stratum. Asterionella comprised the major portion of the 
diatoms. 
LAKES IN CALIFORNIA AND OREGON. 
CRATER LAKE, OREG. 
Crater Lake is situated in the Cascade Mountains of Oregon. It is 104 km. 
(65 miles) north of Klamath Falls and 128 km. (80 miles) east of Medford. 
The lake occupies a geologically recent caldera in a now extinct volcano, 
Mount Mazama (Diller, 1897, 1912). In most places its shores rise sheer to 300 m. 
(1,000 feet) above the lake, and there were but few places where the water could 
be reached without building trails. The lake is nearly round, with an average 
diameter of about 8 km. (5 miles). The area of the lake is given (Diller, 1897) 
