608 Wisconsin Academy of Sciences , Arts, and Letters. 
are large and ovate, terminating in a small mucus reservoir at 
the base of the toes. 
The ganglion is large and saccate. The eye-spot is an aggre¬ 
gation of red pigment granules in a small, hemispherical vesicle, 
which probably represents a rudimentary retrocerebral sac. There 
is no trace of the subcerebral glands. 
Total length 140-160/*; toes 10/*; trophi 15/*. 
Proales parasita is parasitic in Yolvox colonies. The name 
has very frequently been used for another Volvox parasite, Asco- 
morpha volvocicola (Plate), which is much more common. Our 
material was collected in the “Widespread” of the Yahara River, 
between Lake Monona and Lake Kegonsa, south of Madison, Wis¬ 
consin. The two parasites are occasionally found inhabiting the 
same Yolvox colony in apparent peace and amity. The confusion 
of names was started by Gosse in 1852, when he found the animal 
later described by Plate as Hertwigia volvocicola and thought he 
had Ehrenberg’s species; the error was continued in the Rotifera 
and was recently corrected by Rousselet in the Proceedings of the 
Royal Irish Academy, volume 31. 
Proalinopsis Weber 
PROALINOPSIS CAUDATUS (Collins) 
Plate LII, figures 1-5 
Notommata caudata Collins, Science Gossip 1872: 11, text fig -— Mon- 
tet, iRev. Suisse Zool. 23 (1915): 320, PI. 13, fig. 32. 
Covens caudatus Hudson and Gosse, Rotifera (1886) 2: 33, PI. 16, fig. 5. 
—Bergendal, Acta Univ. Lundens. 28 (1892), sect. 2, no. 4, p. 81, 
PI. 4, fig. 25.—Bilfinger, Jahresh. Ver. Naturk. Wiirttemberg 50 
(1894): 45.—Weber, Rev. Suisse Zool. 5 (1898): 461, PI. 18, figs. 
13-15.—Stenroos, Acta Soc. Fauna et Flora Fennica 17 1 (1898): 
130.—de Beauchamp, Zool. Anz. 31 (1907): 910.—Lie-Fettersen, 
Bergens Mus. Aarbog (for 1909) 1910 15 : 42. —Voigt, Siisswasser- 
fauna Deutschlands, pt. 14 (1912): 95, fig. 171 — Lucks, Rotatorien- 
fauna Westpreussens 19*12: 50. 
Proalinopsis caudatus Weber, Weber and Montet, Cat. Invert. Suisse, 
fasc. 11 (1918): 98. 
The body is fusiform, moderately slender, and gibbous poste¬ 
riorly; its greatest width is less than one fourth of the total 
length. The integument is very flexible, but the outline remains 
