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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 punec- 
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. A1- 
_titude, about 12,000 feet. (Chambers, 41.) 
Cypris herricki Turner. 
PLATES LXVII, Fies. 1-10; LXVIII, Figs. 40-42; LXIX, Fics. 32-39. 
1892.—Cypris Herricki C. H. Turner (212), pp. 71-73; Pl. II, Figs. 1-10. 
1893.—Cypris Herricki C. HW. Turner (213), pp. 11-15; Pl. I, Figs. 33-39; Pl. II, 
Figs. 40-42. 
Length 3.0 mm. Height 1.70 mm. Width 1.45 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 
cephalad of this line is usually curved laterad. From within the 
eephalic 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, parallel 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 ashort 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 
is, 
