Marsh — Limnetic Crustacea of Green Lake. 



205 



Cyclops flu vi atilis— continued. 



No. of: 



Total 



No. 



Per cent. 



Coll. 



0-5 



5-10 



10-15 



15-20 



20-25 



25-30 



30-35 



35-40 



40- 



10.96.. 



423 



607 

 546 

 182 

 153 

 331 

 230 

 474 

 368 

 525 

 619 

 369 

 489 

 396 

 253 

 342 

 312 

 400 



92.67 

 96.21 

 85.35 

 39.56 

 31.37 

 99.10 

 55.65 

 18.57 

 32.61 

 50.29 

 51.70 

 23.85 

 29.45 

 51.01 

 28.46 

 25.73 

 in 

 10. 



1.18 



2.63 



13.19 



39.56 



31.37 



5.22 



8.44 

 .54 



4.57 

 11.63 

 19.52 

 11.45 

 12.12 

 17.39 

 12.86 

 0-20 



8. 



2.83 



2.84 



.24 

 .49 

 .19 







.24 

 .34 





11.96.. 



.17 

 .18 



.16 

 .18 





12.96.. 

 13.96.. 



.73 



17.58 

 33.99 

 .60 

 24.35 

 60.76 

 34.78 

 13.71 

 28.43 

 32.52 



8.18 

 14.14 

 22.13 



4.68 

 mete 



8. 



3.30 

 3.27 



3.48 

 10.97 

 30.44 

 16.76 



3.23 

 18.43 

 32.72 

 22.48 

 25.30 



8.19 

 rs. 

 14. 



.18 



14.96.. 













15.96.. 



.30 



.84 



.54 



3.81 



' ' 2.i7 



16.36 



.25 



2.77 



7.02 



42. 











16.96.. 

 17.96.. 



8.69 

 .42 

 .27 

 3.05 

 3.23 

 .27 

 .82 



1.30 





1.31 



18.96 . 







.82 



19.96.. 

 20.96.. 

 21.96.. 

 22.96.. 

 23 96.. 



7.62 



1.62 



1.64 



.61 



.19 



.55 

 .41 



.16 

 1.09 



24.96.. 

 25.96.. 

 26.96.. 

 27.96.. 



.39 



4.68 



2. 



18.72 

 6. 



3.56 

 7.60 



2. 



10.52 



C. fluviatilis (see PI. X) occurs in the collections during 

 the whole year, and generally in considerable numbers. The 

 maximum seems to be reached in the months of October and No- 

 vember, although in 1896 quite large collections were made 

 in July, and the smallest collections were made in the months 

 of May and June. 



C fluviatilis is found in greater or smaller numbers at all 

 depths, but is far the most abundant near the surface, the greater 

 part of the collection being ordinarily within ten meters of the 

 surface, and below twenty-five meters very few are found. In 

 many cases more than fifty per cent, were in the upper five 

 meters. In the winter collections, however, the numbers at the 

 surface were smaller, and the bulk of the collection was fre- 

 quently in the intermediate regions, between ten and thirty 

 meters. There are apparent exceptions to this, however, as in 

 3.95, where 54 percent, were in the upper five meters. But in 

 this case the remaining fifty per cent, was distributed pretty 

 evenly through the deeper regions. 



In order to determine with some degree of exactness the dif- 



