iYRNES: CYCLOPS OF FRESH WATER. 



29 



Foot No. 



Ramus, Outer or Inner.. 



Outer Spines . . 

 Apical Spines . . 

 Apical Seta . . . 

 Inner Seta; .... 



II 



11 







2 



3 



11 

 1 

 1 

 3 



III 



IV 



11 

 1 

 1 

 3 



^seta. 



In the armature of the second and third swimming feet Herrick 

 records two apical setse in place of one apical spine and one apical 

 seta. In this form, however, the long spines are so weak that they 

 sometimes suggest setae, only they are broader. The distinctions 

 between spines and setae are often not very clearly marked in Hnvi- 

 atilis, but this lack of strong differentiation is not attributable to 

 age, since it is found in sexually mature forms. 



"The labrum has about twelve small teeth," according to Herrick. 

 The Long Island form has twelve small teeth between two tooth- 

 like projections at the outer angles of the labrum, making a total 

 number of fourteen. 



Cyclops Bicolor (Plate XIII.) . 



This species was taken but once at Cold Spring Harbor and has 

 not been seen in any of the other collections made on Long Island. 

 It was found in a fresh water pond choked with a dense growth of 

 Utricularia. 



C. bicolor is a comparatively small Cyclops of rather striking 

 appearance. The thorax and abdomen are of a pale yellow color 

 (moon-color"), while the rami of the swimming feet are flushed with 

 a delicate purplish blue. 



The antennae reach barely to the posterior edge of the cephalo- 

 thorax and are provided with several enormously long hairs. They 

 contain each twelve segments. 



The complete armature of the terminal segments of the swim- 

 mingf feet is as follows: 



