ENTOMOSTRACA OF MINNESOTA. 99 
middle of the outer margin, outer terminal seta short, the outer 
median seta as long as the innermost, inner median a little longer. 
Antenne long, slender, reaching the middle of the fourth segment, 
some of itsset greatly elongate, formula,_=_~_=-__-_T Soe peat eee 
the last two segments have a narrow hyaline membrane which is 
entire. Armature of fourth feet as follows: 
ex. 2 spines. ex. 1 seta. 
Outer ramus 0 1 spine, 1 seta. Inner rns 80 2 spines. 
in. 3 Sete. may Pee. 
Fifth foot with short, broad basal joint and an oval elongate apical 
segment bearing two sete. The receptaculum is elongate, with two 
curved proximal branches. Length 0.87 mm. 
Cyclops dybowskii Lande, which seems hardly a good variety of C. 
oithonoides, is said to differ from it in the following major points: 
The antenne are shorter and more stout, minute differences occur in 
the chitin plates which unite the base of the third pair of feet and the 
lamella of the fifth foot. In fact the differences are less than may be 
found in any of our species when collected in different stations. 
Cyclops bisetosus Rehberg. 
RiArk SxOeltly HGS 9-115 
Sars ’62 (bicuspidatus); Rehberg ’80; Forbes ’82 (insectus); Herrick ’84 (insectus); 
Schmeii 792. 
Cephalothorax depressed, first segment of moderate size, angles of 
segments rounded. Abdomen long, its length to that of the thorax 
as 26:39. First segment enlarged, as long as the following. 
Stylets long, lateral seta near the end, small teeth externally and the 
basal one-fourth, inner and outer terminal setze small, median sete 
rather long, the longer as long as the abdomen, the shorter two thirds 
as long. Antenne 17-jointed, little longer than the first thoracic seg- 
ment. Fifth foot resembling that of C. vernalis, with a small but broad 
basal joint with a long lateral seta, apical segment with a long seta and 
short spine. The swimming feet are armed with three spines exter- 
nally (C. pulchellus has but two). Length 1.3 mm. As figured by 
Schmeil, this species differs strongly from C. bicuspidatus and is nearer 
to C. parcus. Whether Cyclops insectus Forbes, is really this species 
must, in the absence of authentic specimens, be left open. 
Cyclops strenuus Fischer. 
PLATE XXIII, Fiaes. 12, 13. 
Fischer ’51; Lilljeborg ’53 (quadricornis); Claus ’57 and ’63 (brevicaudatus, and fur- 
cifer); Sars ’63 (scutifer, abyssorum, and strenuus); Lubbock ’63 (brevicaudatus, 
an clausii); Fric ’72 (brevicaudatus); Uljanin ’75 (vicinus, and fedtschenkoi); 
T 
