406 MR. W. WEST AND PROF. С. $. WEST ON THE 
Tabellaria fenestrata and Surirella biseriata. Much fine detritus was present. 
Rotifers few. 
March 5th, 1909. Temp. of water 41° Е. (=5° C.). Staurastrum jaculi- 
Various Diatoms present, but no single species at all 
ferum uncommon. 
Rotifers and Entomos- 
dominant. Much fine detritus and vegetable hairs. 
traca practically absent. 
April 6th, 1909. Temp. of water 40° К. (=4"4° С), Staurastrum jaculi- 
ferum rather more frequent. Individuals of various groups of the Protococcales 
Fig. 2. 
АОС. SEP | ОСТ. | NOV. | DEC.| JAN. FEB.| MAR. АРК. | MAY JU. | JY. 
1908. 1909. 
o E 
u 17:2? | 10:5? | 15:5? 12:22 | 8:9°| 7-8" 5.5°| 5° 4-4° | 7.8? |12-2? 10:5 к 
| LUUD 
— |, \ L^ |Ссс 
ccc rM Y 
ni \х 
ГА х 1 
" Sd 
/ 4” | 
cc / "d | Г | сс 
А х і EN 
/ x" 1 ÁN 
/ к р / 
К „х \ /] ^ 
М ^ ! 1 
ск * /, J a C 
XN, М fe 
* de 
+ . 
“|; n | 
\ |4 р; 
|+ VA / ; | 
r t РАП r 
+ / М 
t ; i | 
x^ |] 
* 
^ "TH 
+ I+ + | 
+ ` ' + F rr 
rr + ` „7 |; E 
4 v.d. je yt 
+ "SEPA 
+ d 4 I———934 
+ М [А + | 
+ ‚ 11 t 
И | Ё |t H | rrr 
rrr M B | p / + + і 
H 4 t ——— | A x А / * * 
М | = \ 4 H 1 | 
STAURASTRUM JACULIFERUM forma ELAKATOTHRIX GELATINOSA —— 
| TRIRADIATA PERIDINIUM WILLE! —-—:- == 
RHIZOSOLENIA MORSA ++++++++++++ 
SPHAÆROCYSTIS SHROETERI 
Chart of the periodicity of five of the most conspicuous constituents of the phytoplankton 
of Wastwater. The temperatures are in degrees Centigrade. 
beginning to appear. Diatoms practically absent. Much coarse detritus. 
Few Rotifers and a few Nauplii. 
May 3rd, 1909. Temp. of water 46° F. (=7:8° C.). Staurastrum jaculi- 
