582 Wisconsin Academy of Sciences, Arts, and Letters. 
or sac proper, is somewhat triangular in outline, and squarely 
truncate behind; it then contracts abruptly to a fairly large 
cylindrical section, which at the eye-spot again contracts to a 
very slender tube, opening on the corona. The truncate posterior 
end is faintly lobate and opaque, with bacteroids outlining the 
lobes. The subcerebral glands are long and slender, reaching 
some distance beyond the eye-spot, which is at the posterior end 
of the slightly elongate, saccate ganglion. 
Total length 300-325/*,; toes 15/x; trophi 36/*. 
Notommata august a was found rather sparingly in a polluted 
brook at Brick Haven, south of the Potomac River, near Wash¬ 
ington, District of Columbia ; it has not been found elsewhere. 
This species is readily recognized by the slender body, the un¬ 
usual outline of the head, and the structure of the retrocerebral 
organ. 
NOTOMMATA CYRTOPUS (Gosse) 
Plate XLIX, figures 5-8 
Notommata cyrtopus Gosse, Hudson and Gosse, Rotifera (1886), 2: 22, 
PI . 17, fig. 7.—Wierzejski, Rozpr. Akad. Umiej. Wydz. Mat.-Przyr. 
Krakow II, 6 (1893): 228. —Bilfinger, Jahresh. Ver. Naturk. Wiirt- 
temberg 50 (1894): 44. —von Hofsten, Arkiv Zool., Stockholm 6 1 
(1909): 30, fig. 5. —Lie-Pettersen, Bergens Mus. Aarbog (for 1909) 
1910 15 : 39. —Voigt, Susswasserfauna Deutschlands, pt. 14 (1912): 
100, figs. 182, 183.— Mola, Ann. Biol. Lac. 6 (1913): 241. —Weber 
and Montet, Cat. Invert. Suisse, fasc. 11 (1918): 113. 
? RattUMs cimolius Gosse, Hudson and Gosse, Rotifera (1886), 2: 66, 
PI . 20, fig. 14. 
? Notommata distincta Bergendal, Acta Univ. Lundensis 28 (1892), 
sect. 2, no. 4, p. 61, Pis . 3, 4, fig . 23L —Voigt, Forschungsber. Biol. 
Stat. Plon 11 (1904): 39, PI . 3, fig . 18; Susswasserfauna Deutsch¬ 
lands, pt. 14 (1912): 100, figs. 184, 185. 
The body is fairly stout and spindle-shaped, its greatest width 
being a little less than one third of the total length. The integu¬ 
ment is soft and flexible, but the outline remains fairly constant. 
The stomach is usually so crowded with food that it is difficult to 
study the internal organs, even though the animal is really fairly 
transparent. 
There is no separation between the head and neck segments; 
the wudth of the two fused segments is about three fourths of the 
