684 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



water-plants and on floating wood, common — A. E. Yerrill ; Bad River, 

 Lake Superior — J. W. Milner_^(var. with few large papillie, mostly in 

 three rows.) 



Var. d. — Lake Raymond, Nebraska — T. M. Prudden; Lake Okechobee, 

 Florida— Dr. E. Palmer. 



Var. e. — Ecorse, Michigan — J. W. Milner. 



Section B. — Four ocelli. 



No American species belonging to this section are known to me. 



Section C. — Six ocelli. 

 Subsection a. — Back smooth. 



Clepsine pallida Verrill. (Fig. 2, a; head enlarged.) 

 Op. cit. vol. iii, p. 131, fig. 3, a, 1872. 

 Var. a. — Body depressed, broad and obtusely rounded posteriorly, 

 tapering, but not very slender, anteriorly ; about 1 inch 

 long in extension, and 0.15 of an inch broad in contrac- 

 tion. Back smooth, somewhat convex. Head obtuse, 

 with six ocelli, those of the anterior pair nearer together. 

 Acetabulum rather small. Intestine whitish, showing 

 through the integuments, with two large anterior lobes and about six 

 smaller lateral ones. Auditory vesicle very distinct. Color above pale 

 yellowish, with scattered blackish specks, and with a median light line, 

 interrupted by a row of distant, small, black spots. Beneath pale flesh- 

 color. 



Var. h. — Back smooth, grayish green, with two dorsal dark lines, and 

 specked over the whole surface with small blackish dots, which are 

 arranged somewhat in longitudinal lines. Ocelli as in var. a. Length 

 about 0.75 of an inch, (IS""-" to 20""".) Taken September 17. 



West River, New Haven, Conn., both varieties, on submerged wood — 

 A. E. Verrill ; Colorado — Haydeu's expedition ; lake near Long's Peak, 

 elevated 9,000 feet — Hayden's expedition, 1873 ; (var. &, with narrow, 



dark stripes.) 



Subsection h. — Back papillose. 



Clepsine elegans Verrill. (Fig. 2, &; head. See above.) 



American Journal of Science, vol. iii, p. 132, fig. 3 h, Feb., 1872; vol. v, p. 387, 1873. 



Clepsine patelliformis Nicholson, Canadian Journal, 1873. 

 Body depressed, strongly annulated, broadly rounded posteriorly, 

 tapering, but not slender, anteriorly. Length, in extension, about 1.25 

 inches ; breadth, in contraction, 0.20 of an inch. Acetabulum moderately 

 large, projecting considerably beyond the posterior end of the body. 

 Head small, obtusely pointed, white in front and along the edges. Ocelli 

 six, the three pairs close together on the white area of the head, those 

 of the middle pair largest, black. Back covered with distant, slightly 

 elevated, yellow papillae. Color olive-green, thickly specked, especially 

 toward the margins, with purplish brown, and with dark brown trans- 

 verse lines, corresponding with the intervals between the annulations ; 



