710 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [10] 



two setae within. The inner ramus has at the tip. of the last joint one 

 stout spine and one slender seta, one seta without and three setae 

 within. The legs of the second and third pairs are armed alike, the 

 terminal segment of the outer ramus in each bearing a slender seta and 

 two spines at tip (the inner of these the longer, and the seta a little 

 longer still), and one spine without and three setae within. The inner 

 ramus like the outer, except at the tip, where there is a single stout 

 spine and a single seta. In the fourth pair of legs the last joint of the 

 outer ramus bears two terminal spines and one seta, one spine on the 

 outer margin and three setae on the inner. The corresponding joint of 

 the inner ramus is very narrow, has two spines at the tip, one seta 

 without and two setae within. The outer margin of this last segment 

 is minutely hairy above the marginal seta. The rudimentary fifth foot 

 is small, two-jointed, the first joint half as long as the second, twice as 

 broad as long, with a slender simple bristle at the outer distal angle; 

 the second joint with two setae, the outer simple, longer than the pre- 

 ceding, the inner plumose and longest of all. 



By its seventeen-jointed antennae and two-jointed fifth foot with two 

 terminal bristles, this species is related to C. simplex Pog., from which 

 it is, however, readily distinguishable by the shorter last joints of the 

 antennae and the absence of the knife like ridge. The proportions of 

 the joints of the antennules, and the plumose terminal setae of the fifth 

 foot are additional distinctive characters. 



This Cyclops was taken in moderate numbers from Lake Michigamme 



only. 



Cyclops agilis Koch. 



Amer. Nat., XVI (1882), p. 649. 



This wide-spread Old World species, reported from England to Russia 

 and Turkestan, and from Scandinavia to the Tyrol, and also known in 

 this country from Massachusetts to Illinois and Minnesota, occurred in 

 my Lake Superior collections from Marquette. 



Cyclops pectinifer Cragin. 



Trails. Kans. Acad. Sci. (1883) p. 71. 



I have had no difficulty in distinguishing Professor Cragin's species 

 described under this name* from the very closely related form last 

 mentioned, although it is possible that larger collections of both might 

 show them intergradiug. This was the commonest Cyclops in the col- 

 lections made at PAuse. 



Order CLADOCERA. 

 Family Polyphemid^e. 



Polyphemus pediculus L. 



In this curious crustacean, not uncommon in clear shallow lakes and 

 ponds in Europe, we have an example of an immigrant, which has not 



*A Contribution to the History of the Fresh -Water Copepoda. Trans. Kan., Acad. 

 Sci., vill, p. <)G. 



