Harring & Myers—Rotifer Fauna of Wisconsin — II. 527 
The corona is frontal and consists of a marginal wreath of 
strong cilia, interrupted dorsally and closed behind the mouth, 
which is near the ventral edge. The buccal field is in this species 
unciliated and somewhat depressed; its margin is indicated by a 
horseshoe-shaped band of cilia, separating it dorsally from the 
apical plate. 
The mastax belongs to the virgate type, but is somewhat modi¬ 
fied, as the animal is carnivorous and the mallei have become 
adapted to the seizure of prey by prehension through the mouth 
opening. The rami are lyrate in ventral view and have prominent 
basal apophyses for the attachment of the abductor muscles; lat¬ 
erally they are expanded into broad, thin, somewhat asymmetric 
lamellae. Near mid-length they are bent at a right angle; this 
median section is lamellar and denticulate on its inner edge, with 
fine striae continuing for some distance from the base of the den¬ 
ticles. At the apex of the angle there is on each ramus a strongly 
developed tooth, fitting into a groove on the opposite side. The 
dorsal ends of the rami form two powerful, curved, opposing teeth, 
separated from the central, denticulate section by an elongate oval 
opening. The fulcrum is a moderately long, broad lamella, ex¬ 
panded at the base of the rami and nearly parallel-sided poste¬ 
riorly. The unci have a single, powerful tooth, somewhat curved 
and clubbed at the point, and a small accessory tooth, only half the 
length of the main tooth; the basal plate is roughly triangular. 
The manubria have a subsquare basal plate; the central section is 
continued as a nearly straight, slightly compressed rod, curved to¬ 
wards the ventral side at the extreme end. The epiphary nx con¬ 
sists of two triangular plates, bent at a somewhat obtuse angle 
along the median line, and projecting forward at a right angle 
to the rami at the anterior apex. The piston is very large and 
almost completely fills the cavity of the mastax. There are two 
rudimentary salivary glands in the ventral angles of the mastax. 
The oesophagus begins high up on the dorsal side of the mastax; 
its walls are muscular and may be greatly distended to allow the 
passage of entire animals into the stomach. The gastric glands 
are long and ribbon-like; their ends are bifurcate. In addition 
to the glands there are four very long, slender gastric appendages, 
no doubt glandular in nature; two of these are a short distance 
below the gastric glands, the others near the posterior end of the 
stomach. There is no constriction between the stomach and in- 
