North American Fresh-water Cyclopidce. 41 



Var. brevispinosus Herrick. 

 (PL XL, Fig. 1 and 2.) 



Cyclops brevispinosus, Herrick. '84, p. 148, PL S. Fig. 7-11. 

 Cyclops brevispinosus, Marsh, '93, pp. 205-206, PI. IV., Fig. 11. 12. 

 Cyclops brevispinos us, Herrick and Turner. '95, p. 95, PI. XXIII., 

 Fig. 1-4: XXIV., Fig. 7-12. 



This species of Herrick's, which I reduce to a variety, is dis- 

 tinguished from typical C. viridis, as follows: 1. By the 

 form of the outer terminal spine of the stylet, which is short, 

 broad, and knife-like. This form of spine is connected in 

 series (PL XL, Fig. 1) with the slender spine of the variety 

 insectus. 2. By the fifth foot (PL XL, Fig. 2). In this 

 appendage the small spine is never a part of the segment as it 

 may he in the European viridis and always is in the American 

 form. This spine is also longer than in riridis and is lanceolate 

 in shape. 3. By the armature of the swimming feet. The 

 spines of these appendages are extravagantly long and heavy. 

 While at first sight these differences might seem sufficient for 

 the complete separation of the two forms, the distinguishing 

 characters are in most species of Cyclops so variable that it 

 seems to me best to consider brevispinosus as merely a variety. 



The receptaculum sen/in is is as in insect us. 



I find this variety in collections from Lakes Michigan, 

 Manitoba, Okoboji, (Iowa) ; and from Lake Winnebago, Green 

 Lake, and Lake Geneva in Wisconsin; from Swan Lake in 

 Montana, and Lake Pend d'Oreille in Idaho ; from the Detroit, 

 Calumet, and Illinois Livers; and from Sand, Fox, Quiver, 

 Dogfish, Phelps, and Thompson's lakes — all in Illinois. It 

 is never especially abundant but seems to lie quite generally 

 distributed. 



Var. insectus Forbes. 

 (LI. XL, Fig. 3-6.) 



Cyclops insectus, Forbes, '82a, p. U49. PI. IX.. Fig. i>. 

 Cyclops parous, Herrick, *S2a, p. 229, PI. VI.. Fig. 12-15. 

 Cyclops insectus, Herrick. '84, pp. 151, 152, PJ. U, Fig. 9. 

 ( 'yclops viridis, Cragin, '83, p. 68, PI. IV., Fig. 8-16. 

 < 'yclops unlangulatus, Cragin, '83, p. 71, PI. IV., Fig. 17. 

 Cyclops insectus, Sehmeil, '92, p. 95. 



