104 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 



Eudimentary legs of fifth pair distinctly articulated, basal article 

 with a long seta at its outer distal angle, and second article with two 

 setee at its blunt tip, the outer the longer. From Duck lake. 



Neither figures nor measurements are given, and the form of the 

 fifth foot is left to conjecture. In this difficult section of the genus 

 it is very hard to place species even when all the details are clearly 

 before us. The original description is reproduced with only verbal 

 alteration for the sake of brevity. 



* Cyclops forbesi Herrick. 

 Forbes '93 (serratus*). 



A very long, narrow, loosely articulated species with strikingly 

 salient thoracic angles. Cephalothorax broadest far forward and 

 lobed in front, between the 17 jointed antenna. Abdomen long and 

 slender, with very long and narrow caudal rami, and but two devel- 

 oped setfe to each ramus. The first segment is but little longer than 

 wide (eight to seven), is broadest across the middle, and excavate in 

 front at the base of each antenna, leaving a thick, median, projecting 

 lobe. The second segment is nearly a fourth as long as the first, and 

 but little narrower, broadest across its posterior angles, which, though 

 blunt, are so strongly salient that the lateral margins are decidedly 

 sinuate. The third segment is as long as the second, but narrower^ 

 and with its sides more nearly parallel. The fourth and fifth seg- 

 ments are progressively shorter and narrower, the latter being trape- 

 zoidal, as seen from above, and separated from the first abdominal 

 segment by a deep acute emargination. 



The abdominal segments areas long as the cephalothoracic segments 

 two to five taken together, and the furca is as long as the last three 

 segments. The first segment of the abdomen is broadest in front, 

 where its width is nearly as great as its length. The second is as 

 broad as long, the third and fourth equal, the fifth a little shorter, the 

 last with a row of fine spinules around the base of the rami. The 

 width of each ramus is contained nearly eight times in its length. 

 Besides the lateral spine, situated a little before the posterior third of 

 the ramus, there is a cluster of two or three minute spines at its an- 

 terior fourth. The outer and inner terminal setse are reduced to short 

 subequal spines about twice as long as the ramus is wide. The other 

 setse are slender, plumose, the inner nearly twice as long as the outer. 

 The antennte are rather stout and short, 17-jointed, reaching to the 

 end of the second segment. They are without special structures or 

 appendages. [This probably means armed as usual, but without 

 knife ridges or spurs.] Armature of the legs as follows : 



* This- name is preoccupied by C. serratus Pratz. 1866. 



