THIRD FEET. 
seta. 
spine, 1 seta. 
sete. 
ex. 1 spine. 
ap. 2 spines, 1 seta. Inner ramus 
in. 3 sete. 
Outer ramus 
ENTOMOSTRACA OF MINNESOTA. 105 
First FEET. 
ex. 1 spine. ex. 1 seta. 
Outer ramus jap. 1 spine, 1 seta. Inner ramus + ap. 1 spine, 1 seta. 
Inve 2) Sete. in. 3 sete. 
SECOND FEET. 
ex. 1 seta. ex. 1 seta. 
Outer ramus { ap. 1 spine, 1 seta. Inner ramus jap. 1 spine, 1 seta. 
in. 3 sete. Ins for setees 
= 
S 
oo ee 
FouURTH FEET. 
ex. 1 spine. ex. 1 seta. 
Outer ramus jap. 2 spines, 1 seta. Inner ramus 5 ap. 2 spines. 
in. 3 sete. in. 2 sete. 
The fifth feet are two-jointed, the basal joint broad, quadrate, with 
a seta at its outer angle; the second cylindrical, with one long and one 
short seta at tip. Length, without sete, 1.34 mm. 
*Cyclops signatus Koch. 
PLATES XX, Fies. 8-11, 21; X XI, Fra. 16. 
Jurine ’20 (monoculus quadricornis albidus and m. g. fuseus); Koch ’41 (signatus, 
and annulicornis); Baird ’50 (quadricornis var. b and var. c); Claus ’57 and ’63 
(coronatus and tenuicornis); Sars ’63 (anuulicornis, tenuicornis, and signatus) ; 
Lubbock ’63 (coronatus, and tenuicornis); Fric ’72 (coronatus, and tenuicornis) > 
Poggenpol ’74 (clausii); Uljanin ’75; Hoek ’78 (coronatus, and signatus) Brady ’78 
(tenuicornis, and signatus); Cragin ’83 (tenuicornis, and C, signatus fasciacornis) 5 
Herrick ’82 and ’84 (tenuicornis); Daday ’85 (tenuicornis, and signatus); Vosseler 
’86 (tenuicornis, and signatus); Forbes ’87 (gyrinus); Sostaric ’88 (fuscus); Thall- 
witz ’90; Lande ’90; Schmeil ’91 (albidus); Brady ’91; Richard ’91 (fuscus, annul- 
icornis, and tenuicornis); Schmeil ’92 (fuscus, and albidus); Marsh '92; Turner ’92 
(tenuicornis). 
Of the identity of the two varieties which have so long been recog- 
nized as distinct species (C. tenuwicornis and O. corvnatus) the writer 
has little doubt. The development history has been traced sufficiently 
to settle this point. This combination was first made by the writer, 
and not by Brady, as Marsh implies. Cephalothorax large and broad, 
considerably longer than the abdomen. First thoracic segment large, 
more than half as long as the whole thorax, Abdomen rather short, 
cylindrical. Stylets short and not tapering, shorter than the preced- 
ing abdominal segment. Sete very plumose, three of them long, the 
longest being about as long as the abdomen, the innermost being 
nearly half as long and the outermost apical seta short. In the male 
the first thoracic is much longer and the abdomen relatively shorter. 
Antenne long and the terminal joints attenuated, the last three being 
armed by hyaline plates. Fourth foot with the following armature: 
