208 Marsh — Gi/clopidce and Calanidce of Wisconsin. 



separating our American form from C. pidchellus Koch, or bicus- 

 pidatus Claus. All the European descriptions agree very closely 

 with our form. We find in C. thomasi the same variations which 

 Vosseler records in the European form, — for example, the vari- 

 able position of the lateral spine of the furca. In general form,, 

 length of antennae, form of furca and armature of swimming- 

 feet and fifth feet, it is difficult to find any clear distinction, 

 between the forms of the two continents. I cannot agree with 

 Herrick and Brady in considering G. bisetosus Rehberg a syno- 

 nym of pulchellus, for pidchellus has the swimming feet armed 

 with two spines externally, while bisetosus has three, and my 

 observations lead me to think that the armature of the swim- 

 ming feet is quite constant. 



The armature of the terminal joints of the swimming feet is. 

 as follows : 



FIRST FOOT. 



Outer br. ex. 2 spines. Inner br. ex. 1 seta. 



ap. 2 setae. ap. 1 spine, 1 seta, 



in. 2 setae. in. 3 setae. 



SECOND AND THIRD FEET. 



Outer br. ex. 2 spines. Inner br. ex. 1 seta. 



ap. 1 spine, 1 seta. ap. 1 spine, 1 seta, 



in. 3 setae. in. 3 setae. 



FOURTH FEET. 



Outer br. ex. 2 spines. Inner br. ex. 1 seta. 



ap. 1 spine, 1 seta. ap. 2 spines, 



in. 3 setae. in. 2 setae. 



G pidchellus occurs everywhere in the great lakes in pelagic- 

 collections, and in some of the smaller lakes of Wisconsin. 



Cyclops parous Herrick. 



Plate IV, fig. 16; plate V, fig. 1. 



1882. G parcus Herrick (23), p. 229, pi. VI, figs. 12-15. 

 1884. << ',< " (26), p. 148, pi. R, fig. 22. 



G parcus, in the armature of the swimming feet is like G 



pulchellus and G navus, while its fifth feet are like those of G 



americanus and G. brevispinosus, although the basal joint is- 



