Harring and Myers—The Rotifers of Wisconsin. 
577 
two sides are nearly equally developed. The fulcrum is very 
long, stout, and slightly tapering for two thirds of its length; 
the posterior third is obliquely truncate and slightly incurved 
at the tip. The oblique ventral edge has a Y-shaped groove, the 
sides of which are formed by two thin, corrugated laminae, which 
provide increased surface for the attachment of the muscles. 
The anterior end of the fulcrum has a rounded projection at the 
base of the rami; immediately behind, the right ramus has a very 
broad, lamellar tooth curving diagonally towards the left; the 
free edge has a finely striated border. The left ramus is deeply 
excavate opposite this tooth and has at its extreme anterior point 
two large, blunt teeth, interlocking with two similar teeth on the 
right ramus; the decurved dorsal section of the rami beyond the 
anterior teeth is not denticulate. The left alula is fairly large and 
strongly curved; the right is a small, conical knob. The left uncus 
has a very large ventral tooth, clubbed at the point and with a 
rudimentary pre-uncial tooth, lamellar at the tip, attached to its 
ventral edge; the second tooth is very much smaller and shorter; 
the third and fourth teeth are closely appressed and, like the 
fifth tooth, linear. The basal plate unites all the teeth nearly 
to their tips and projects considerably beyond the ventral tooth. 
The right ramus has a linear pre-uncial tooth and the first and 
second teeth of nearly equal size, but much smaller than the left 
ventral tooth; the third and fourth teeth are but little more than 
half as long. The basal plate projects very little beyond the pre¬ 
uncial tooth. The manubria are very broad and lamellar an¬ 
teriorly, terminating in a rather narrow, straight median branch. 
Below the posterior edge of the rami there is a long, incurved rod 
imbedded in the walls of the mastax; the ventral end rests on the 
inner surface of the ramus, and the dorsal ends meet some distance 
below and behind the tips of the rami. 
The oesophagus is long and slender. Gastric glands, stomach- 
intestine, and ovary are normal. The bladder is very small. The 
foot glands are rather small, very slender, and slightly club- 
shaped. 
The retrocerebral sac is extremely large, nearly circular, flat¬ 
tened and disk-shaped; the duet is a very long, slender tube. The 
subcerebral glands are large and pyriform, reaching to the level 
of the eye-spot; they usually contain bacteroids. The ganglion 
is elongate and quite slender. 
Total length 300-375/*; toes 25-30/*; trophi 65/*. 
37—S. A. L. 
