296 
Birge—Notes on .Cladocera. 
Schoedleri , Sars. It is not improbable, however, that both spe¬ 
cies are varieties of the same form. The figures show, besides 
the head of the male, the post abdomen and caudal claw of the 
female, and two characteristic types of outline of 'the head of 
the female. 
Dapiinia Kahlbergjensis Schdl.,, var. breviceps, var. nov. 
Plate XI, Figs. 1, 2, 3, 6. 
Female.—The animal is hyaline and the macula nigra is want¬ 
ing. The species thus belongs to the section Hyalodaphnia of 
Schoedler. The head is small, rounded in front and has a nar¬ 
row crest. The rostrum is small, but always projects beyond 
the sense-hairs. The valves are broadly oval in form and are 
faintly recticulated. The spine is slender and of moderate 
length. The first and second abdominal processes touchy and 
are slightly united at the base. The post abdomen has the 
form characteristic of the section Hyalodaphnia. It bears 9-10 
anal teeth, which are recurved and decrease in size from the 
posterior end of the row. The caudal claws are provided with 
the usual two teeth on their anterior (ventral) margin. They 
have a pecten of fine teeth at the base, extending a little way 
upon the claw. This is immediately followed by a second pec¬ 
ten of 10-12 coarser teeth, which are longest in the middle. 
Very fine denticles extend to the end of the claw. 
Length, 1.4 mm., including spine of 0.3 mm., height, 0.7 mm. 
The male was not found. 
The length of the head is variable, but may be a little more 
than one-fourth of the valves. Its anterior margin varies from 
a form evenly rounded to one extending into a blunt point, as 
is shown in the figures. The ventral margin of the head varies 
from nearly straight to markedly concave, and the rostrum may 
be merely a blunt, rounded termination or may be drawn out 
into a well defined pointed, projection. The antennae are slender 
and rather weak, not unusually long. When turned back the 
ends of the setae do not reach the hinder margin of the valves. 
The basal joint of the antennae extends beyond the anterior 
margin of the head in some individuals and in others falls short 
