Harring and Myers—The Rotifers of Wisconsin. 591 
broad, roughly triangular lamella; the posterior half is a slender 
rod, slightly expanded at the tip and curving towards the ventral 
side. The oesphagus is unusually short. The gastric glands, 
stomach-intestine, ovary, and bladder are normal. The foot glands 
are fairly large and pyriform. 
The retrocerebral sac is moderately large and nearly spherical; 
it usually contains a sufficiently large number of bacteroids to 
render it virtually opaque. The ganglion is large and saccate 
with the eye-spot at its posterior end. 
Total length 175-200/*,; toes 18-20/*,; spur 16-22/*,; trophi 30y. 
Notommata tripus is common everywhere among the minute 
algae covering submerged water-plants. 
Ehrenberg cites as a doubtful synonym Vorticella felis Muller 
and its later transformations at the hands of Schrank and 
Lamarck; it has been included here also, for the sake of complete¬ 
ness, although Muller’s figure shows perhaps more resemblance to 
a Mytilina (= Salpina) than to Notommata tripus. 
Notommata Venusta Harring and Myers, new species 
Plate L, figures 1-4. 
The body is rather short and moderately stout without any 
very prominent external characteristics. The integument is soft 
and flexible, but the outline is nevertheless quite constant. 
The head and neck are not distinctly separated; an in¬ 
conspicuous fold marks the junction of the neck and abdomen. 
The latter is slightly enlarged posteriorly and tapers rather ab¬ 
ruptly to the foot, which is composed of two short, slender joints, 
the anterior one a little larger than the posterior. The tail is 
small and indistinct, with a single rounded, median lobe. The 
toes are about one fifteenth the length of the body, almost straight 
and unusually slender, tapering to very acute points. . The 
dorsal and lateral antennae are small setigerous pits in the normal 
positions. 
The corona continues down the ventral side of the body about 
one fourth the length and terminates in a slightly projecting chin. 
The auricles are small and continuous with the corona. 
The mastax is virgate with unusually slender and strongly 
asymmetric trophi. The moderately long fulcrum is large at the 
