Barring & Myers—Rotifer Fauna of Wisconsin — 11. 455 
The mastax is virgate and the trophi slender and strongly asym¬ 
metric, the left side being more strongly developed than the right. 
The fulcrum is long and slender and tapers towards the posterior 
end, which is slightly enlarged and bent inwards, providing attach¬ 
ment for the muscles of the piston. The rami appear triangular in 
ventral view and are bent nearly at a right angle at the extreme 
anterior point. The left ramus has near the base a prominent, 
blunt tooth on its inner edge, and immediately behind this a broad, 
lamellar and finely striated tooth. Near the anterior angle there 
are two large teeth, separated by a slight interspace. The right 
ramus is coarsely denticulate; about eight rudimentary teeth are 
present. The left uncus has a large ventral tooth, followed by a 
much smaller and shorter second tooth; the right uncus has a 
similar ventral tooth, followed by two smaller teeth; the basal 
plates are somewhat triangular in outline and bordered by a mar¬ 
ginal rib. The manubria have a subsquare basal plate, with a 
straight posterior branch ending in a triangular, plate-like ex¬ 
pansion. The piston is large and fills the entire cavity of the 
mastax. 
The oesophagus is moderately long and begins high up on the 
mastax. The gastric glands, ovary and bladder are normal. There 
is no distinct separation between the stomach and intestine. The 
foot glands are small and pyriform. 
The ganglion is moderately large and saccate. The retrocerebral 
organ consists of a rather small, pyriform sac, usually opaque with 
bacteroids. The eyespot is at the posterior end of the ganglion. 
Total length 225-275/x; toes 25~30/>i; trophi 36/>t. 
Taphrocampa selenura is widely distributed, but always in small 
numbers. It is closely related to Taphrocampa annulosa, but is 
readily distinguished by its larger size, as well as by the peculiar 
form of the toes and the more robust trophi. 
TAPHROCAMPA CLAVIGEEA Stokes. 
Plate XXIV, figures 1-4. 
Taphrocampa clavigera Stokes, Ann. Mag. Nat. Hist., ser. 6, vol. 18, 1896, 
p. 18, pi. 7, fig. 2. 
The body is elongate, fusiform and very slender; its greatest 
width is about one sixth of the total length. The integument is 
soft and very fiexible and the outline is constantly changing. 
There is no distinct separation between the head and abdomen; 
the contracted animal is marked with evanescent annulations, 
