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



one twenty-fifth high, as in virens. In ventral and dorsal view it 

 also resembles virens. Surface smooth pubescent, with minute punc- 

 tures. Color bright deep green." (Chambers.) 



This species has not been seen by me. It certainly is very closely 

 related to Cypris virens, and may prove to be that species. For the 

 present, however, it is thought best to regard it as a distinct species. 



Habitat: Pond fed by melting snow, Mount Elbert, Colorado. Al- 

 titude, about 12,000 feet. (Chambers, 41.) 



Cypris lierricki Turner. 



Plates LXVII, Figs. 1-10; LXVIII, Figs. 40-42; LXIX, Figs. 32-39. 



1892. — C^pm HerricU C. H. Turner (212), pp. 71-73; PJ. II, Figs. 1-10. 

 W^'i— Cypris Herricki C. 11. Turner (213), pp. 11-15; PI. I, Figs. 33-39; PI. 11^ 

 Figs. 40-42. 



Length 3.0 mm. Height 1.70 mm. Width 1.43 mm. 



In a lateral view, the shell is sub-triangular, highest near the mid- 

 dle. The ventral margin is straight, excepting at the cephalic ex- 

 tremity, where, after a shallow concave notch, the margin is convex. 

 The remainder of the margin is strongly convex." From the above 

 described ventral notch, a well defined, feebly convex, line passes 

 dorsad to the opposite margin. That portion of the shell which lies 

 ceplialad of this line is usually curved laterad. From within the 

 cephalic and caudal extremities of the valves numerous hairs pro- 

 trude. 



In a dorsal view, the shell is sub fusiform, being widest caudad of 

 the middle. At their caudad extremity the valves are slightly divari- 

 cated, while at their cephalad extremity they are closely approximated. 

 The shell is covered with fine reticulations and minute hairs. In addi- 

 tion to these, it is marked with conspicuous dark green bands. These 

 bands are arranged as follows: One, paiallel to and almost adjacent 

 to the mesal border of the shell, extends from the caudo-ventrad angle 

 of the shell dorso-cephalad almost to the cephalad extremity of the 

 valve. There it divides. One portion continues in the same course 

 to the cephalo ventral extremity of the valve. The other, turning 

 laterad, passes ventrad for a short distance and terminates in a sharp 

 point. At the origin of this line there is a large, convex blotch, which 

 extends ventrad a short distance. Near the centre of the figure several 

 bands fuse in such a manner as to form a hollow, sub-square figure. 

 From the cephalo- dorsal corner of the square a tongue passes ventro- 

 caudad into the square. The length of this tongue and the angles it 

 makes with the sides of the square vary slightly in different individ- 

 uals. Usually it extends almost to the centre. From this same angle 

 of the shell a band projects ectad. After passing cephalad a short 



