150 THE AMERICAN NATURALIST. [VOL. XXXIX. 
Difflugia constricta (Ehrenberg). 
Test usually of coarse sand grains; a yellow or brown 
chitinous membrane with irregularly scattered sand particles 
noted in one or two cases. 
Sise.— Length, 80-102 p; breadth, 59-75 „a; aperture 
22-37 p. 
Localities. — Lake of the Clouds (B. S. N. H., no. 4319) ; 
Claremont (B. S. N. H., no. 4662); Squam Lake (Cushman 
Coll. no. 199); North Woodstock (Henderson Coll., no. 62). 
Difflugia spiralis Ehrenberg. 
Test of varying construction, in one or two cases built up of 
the vermiform chitinous pellets shown in Leidy’s Plate 19, fig- 
ure 7; in others, of fine, straight, spicule-like fragments. In 
one, many diatom valves were used. The neck showed much 
variation in length. 
Size. — Length, 44-126 u; breadth, 38-96 mw; aperture, 
12-46 u. 
Localities. — North Woodstock (Cushman Coll, nos. 182, 
183, 190); Squam Lake (Cushman Coll, no. 197); Gilmore 
Pond near Profile House (B. S. N. H., no. 4314). 
Hyalosphenia cuneata Stein. 
Test of delicate chitinoid membrane, colorless and unorna- 
mented. 
Size. — Length, 60 u; breadth, 42 u; aperture, 24 u. 
Locality. — North Woodstock (Henderson Coll., no. 5 3). 
Hyalosphenia papilio Leidy. 
a a delicate and beautiful case of light straw-colored 
chitin. 
Size. — Length, 111-118 p; breadth, 67-69 m; aperture, 
31-32 p. 
Localities. — Mt. Munroe (Henderson C i 
à oll., no. 102) ; Mirror 
Lake, Chatham (Cushman Coll., no. 1 57). 
