572 Wisconsin Academy of Sciences, Arts, and Letters. 
NOTOM MATA CERBERUS (GoSSe) 
Plate XLVI, figures 5-8 
Covens cerberus Gosse, Hudson and Gosse, Rotifera (1886) 2: 34, PL 
16, fig. ,3.—? Skorikov, Trav. Soc. Nat. Kharkow 30 (1896): 289.— 
L.ib-’Pettersen, Tromso Mus. Aarsh. 33 [1911 (for 1910)]: 57. 
Notom mat a cerberus be Beauchamp, Zool. Anz. 33 (1908): 401, figs. 
1-3.— Voigt, ;Siisswasserfauna Deutschlands, pt. 14 (1912): 97, 
fig. 174.— Weber and Montet, Cat. Invert. Suisse, fasc. 11 (1918): 
lOS. 
The body is fairly slender, its greatest width being from one 
fourth to one fifth of the total length. The integument is rather 
flexible, but the outline is quite constant. 
The head and neck are rather narrow and slender; there is a 
slight transverse fold between the head and the neck, and also one 
between neck and abdomen. The abdomen is elongate and very 
slightly tapering to a point about two thirds its length, from 
where it decreases gradually in width to the base of the foot. The 
tail is rounded and has a small but distinct median notch and a 
shallow, rounded lateral sinus which separates the median lobe 
from the rudimentary lateral lobes. The foot has two short joints, 
the posterior one carrying a very small tuft of setae. The toes 
are of moderate length, about one fifteenth of the total length; 
they are slender, tapering, slightly compressed laterally, and end 
in acute points; the ventral edge is almost straight, and the dorsal 
slightly decurved. 
The corona extends down on the ventral side about one fourth 
the length of the body; the post-oral portion forming a small chin. 
The auricles are short and stout, with robust tufts of cilia, not 
continuous with the corona. 
The dorsal and lateral antennae are small setigerous pits in the 
normal positions. On the second foot joint there is, on the dorsal 
side, immediately above the base of the toes, a small circular pit 
with a few setae in its center. 
The virgate mastax is of the normal, pumping type, and the 
trophi are robust and somewhat asymmetric. The fulcrum is of 
moderate length, straight, and tapering towards the posterior 
end, which is slightly crutched and formed of two lamellae 
joined in a Y-shaped section, to which the muscles of the piston 
are attached. The right ramus has a fairly deep, ventral, trans¬ 
verse groove, in front of which there is a broad, subsquare 
