ENTOMOSTRACA OF MINNESOTA. 91 
tion than once supposed, C. ingens was united with C. gigas as an un- 
named variety of C. viridis (Herrick’84, p. 145). The preimago stage 
is similar to that of gigas, and this fact made the union seem more 
legitimate. Still later Marsh, without recognizing the varietal differ- 
ences and having only the smaller form before him, erects for it a new 
species, C. americanus. Of course, if this is to include the whole 
assemblage representing C. viridis in America, the name C. ingens is 
prior. If not, the later name may be revived for the form correspond- 
ing to C. gigas of Europe. 
To judge from the figures in Claus’ Das Genus Cyclops, the European 
form is subject to a very wide range of variation, for C. furcifer, after- 
wards regarded as a simple varietal form of C. brevicaudatus, has the 
stylets and antennz greatly elongated. Unfortunately the details of 
the armature of the feet are not given by Claus or most of the authors 
following him. 
Var.a. *Cyclops americanus Marsh. 
Pa AT OEY 
Subspecies Americanus Marsh. 
We quote Marsh’s description entire: 
‘‘Cephalothorax oval, the first segment being about half its total 
length. Antenne 17-jointed, about as long as the first cephalathoracic 
segment. Abdomen rather slender, the last segment armed on its 
posterior border with small spines, All the abdominal segments in 
immature individuals are strongly pectinate posteriorly. Furca 
about three times as Jong as its average breadth, the lateral spine sit- 
uated well towards the end. The first and fourth terminal sete are 
short, slender and plumose, nearly equal in length. Of the internal 
setce, the outer is a little more than three-fourths of the length of the 
inner. The armature of the terminal joints of the swimming feet is 
as follows: 
First Foor. 
ex. 3 spines. ex. 1 seta. 
Outer ramus | 2 sete. Inner ramus {i 1 spine, 1 seta. 
in. 2 sete. in. 3 sete. 
SECOND AND THIRD FEET. 
ex. 3 spines. 1 seta. 
Outer ramus {se 1 spine, 1 seta. Inner ramus | 1 spine, 1 seta. 
in. 3 sete. 1 3 sete. 
FouRrtTH Foor. 
ex. 3 spines. ex. 1 seta. 
Outer ramus {sp 1 spine, 1 seta. Inner ramus | 2 spines. 
in. 3 sete. in. 2 sete. 
‘‘Fifth foot two-jointed, basal joint very broad, armed with one 
seta. Terminal joint armed with a seta and a blunt spine. Length 
1.2 mm.”’ 
