173 
hypothesis of Wesenberg-Lund (’00) we should expect a predomi- 
nance of the long-spined forms. 
Brachwonus bakert var. rhenanus Laut.—Average number of 
females, 118; of eggs, 138; but more abundant in previous years. 
This is the third in numbers on the list of seven varieties, being 
surpassed only by clumtorbicularts and tuberculus. It includes about 
one sixth of the individuals referred to this species. It is found 
throughout the whole range of the seasonal distribution of the 
species and exhibits the same peculiarities noted in cluntorbicularis, 
to which it is very closely related. The proportion of females to 
eggs noted in this variety is very large; 5,284 to 5,485 in the grand 
total. 
Brachionus bakert var. brevispinus Ehrbg.—Average number of 
females, 795; of eggs, 390; but somewhat more abundant in previ- 
ous years. It was found throughout the whole seasonal range of 
the species, but not quite so abundantly in the latter as in the earlier 
half of the summer, resembling in this particular the type. The 
number of eggs carried in this species is in relation to the number of 
females less than usual—3,906 to 795. 
Brachonus bakert var. melhemt Barrois and v. Daday.—Average 
number of females, 49; of eggs, 49. More abundant in previous 
years, especially in 1894, when it constituted over a fifth of the 
individuals (25,764) in the largest pulse recorded for the species as a 
whole—122,958 on July 30. Inthe aggregate in all years it includes 
only about a ninth of the individuals referred to the species. This 
form was originally described from Syria, but it is found in great 
perfection in our plankton, even in the extreme type described by 
Zacharias (98b) as B. falcatus. It occurs throughout the whole 
seasonal range of the species, its distribution being somewhat similar 
to that of tuberculus. I do not find any constant tendency limiting 
its occurrence to any part of the seasonal range. 
Brachionus bakert var. tuberculus Turner.—Average number of 
females, 155; of eggs, 42; but very much more abundant in previous 
-years, especially in 1894, when it constituted almost half (55,332) of 
the largest pulse of the species (122,958). This, the most divergent 
of all the varieties, constitutes over a third of all the individuals 
referred to the species. It occurs throughout the whole seasonal 
range of the species, though the larger numbers were found in 
1894-97 in the earlier part or middle of the summer. I find nothing 
