Harring and Myers—The Rotifers of Wisconsin. 
563 
tuft of minute setae. The toes are moderately long, about one 
sixteenth of the total length, slender, conical, and slightly de- 
curved. 
The dorsal antenna is spindle-shaped and very long; it is 
sharply constricted at the base and has a tuft of setae at the 
tip. The lateral antennae are short tubules with a few extremely 
long setae. 
The corona has a median, trough-like depression throughout its 
length; the post-oral portion projects from the body as a long, 
conical, bluntly pointed chin. The auricles are tubular and ex¬ 
tremely long; only the ends are ciliate. The width across the 
fully extended auricles is more than twice the normal width of 
the head segment. 
The mastax is of the normal virgate type, with strongly asym¬ 
metric trophi, much more robust on the left side than on the 
right. The fulcrum is very long and stout, tapering from the 
base to the posterior end, which is slightly incurved. The posterior 
half of the fulcrum is Y-shaped in cross-section, as two thin lamel¬ 
lae, gradually increasing in width, project diagonally outwards 
and provide increased surface for the muscles of the piston. The 
rami are irregularly triangular in ventral view and are strongly 
curved longitudinally, so that their posterior edge is nearly at a 
right angle to the fulcrum. Near the base of the rami there is a 
rather prominent, triangular median projection; immediately be¬ 
hind this the right ramus has a broad, lamellar tooth projecting 
diagonally towards the left; the margin is coarsely denticulate. 
The left ramus is deeply excavate opposite this tooth. The alulae 
are very large and well developed. The left uncus has a very 
large, ventral tooth, clubbed at the tip, and followed by three 
much smaller, slightly divergent teeth; at the dorsal margin of 
the lamella uniting all the teeth there is a rudimentary fifth 
tooth. The right uncus has four teeth, unequally developed, but 
much less so than the mating teeth on the opposite side. The 
manubria are very long and broad, the posterior ends curving 
inwards and towards the dorsal side. Immediately below the 
posterior margin of each ramus a curved rod is imbedded in the 
walls of the mastax; the ventral end rests on the inner surface of 
the ramus, and the dorsal ends meet below the tips of the rami. 
The oesophagus is very long and slender. The gastric glands, 
stomach-intestine, and ovary are normal. The bladder is formed 
