Earring & Myers—Rotifer Fauna of Wisconsin — II. 461 
PLEUROTEOCHA KOBUSTA (Glasscott). 
Plate XXV, figures 5-8. 
Microcodon robustus Glasscott, Proc. Eoyal Dublin Soc., new ser., vol. 8, 
1893, p. 40, pi. 3, fig. 2. 
Microcodides robustus Eousselet, Journ. Quekett Micr. Club, ser. 2, vol. 6, 
1895, p. 121, pi. 6, fig. 1. 
? Microcodides abbreviatus Stenroos, Acta Soc. Fauna et Flora Fennica, vol. 
17, No. 1, 1898, p. 113, pi. 1, fig. 20. 
Mikrocodides robustus Harking, Bull. 81 IT. S. Nat. Mus., 1913, p. 71. 
The body is short, stout and gibbous; its greatest width is about 
two fifths of the entire length. The integument is leathery and 
the outline remains quite constant. The entire body is very trans¬ 
parent. 
The head and abdomen are separated by a deep constriction. 
The head segment is short and very broad; its width is about two 
thirds of the greatest width of the body. The abdomen is globose 
and ends in a short, sleeve-like tail surrounding the base of the 
foot. On the posterior half of the abdomen are five or six well 
marked longitudinal folds; they are continuous from side to side 
and not interrupted posteriorly. The foot is long, stout and 
slightly tapering; it has three joints of approximately equal 
length. The toe is single and abruptly reduced near the middle; 
its length is a little less than one tenth of the total length of the 
animal. As there are two well developed foot glands it is evident 
that the single toe is a result of the fusion of two originally sep¬ 
arate toes. 
The dorsal antenna is a large, knoblike elevation on the pos¬ 
terior part of the head, immediately in front of the neck; it has a 
funnel-shaped central depression with a small tuft of sensory 
setae. The lateral antennae are minute tubules with a few very 
short setae in the normal position. 
The corona is oblique and consists of a circumapical band of 
cilia with two lateral, auricle-like tufts of strong cilia adapted to 
swimming; the buccal field is evenly ciliated. The mouth is in the 
normal position, near the ventral margin of the corona, and not 
in the center, as stated by Eousselet. 
The mastax is virgate and of very simple form. The fulcrum 
is very long, slender and tapering; the posterior end is slightly 
expanded for the attachment of the muscles of the piston. The 
rami are roughly triangular and without teeth or denticulations; 
a somewhat abrupt bend divides them into a rather short ventral 
