Earring and Myers—The Rotifers of Wisconsin. 629 
The corona extends down on the ventral side about one fourth 
of the length of the body; the post-oral portion projects as a 
prominent chin. The auricles are very large and powerful; in a 
frontal view they appear as nearly circular discs of a diameter 
equal to their length and much compressed in the longitudinal 
direction of the body. The coronal cells are very conspicuous 
through the rather sparse ciliation of the buccal field. 
The mastax is of the type of L. truncata (Jennings) and has 
the same triangular outline due to the presence of two large, 
ventral salivary glands that occupy the space in the ventral angles 
of the mastax, between the fulcrum and the manubria. The rami 
are of the normal, lyrate form with large alulae and a right-angled 
dorsal extension of moderate length, serving for the support of 
the unci. The fulcrum is of nearly the same length as the rami 
and tapers gradually to the posterior, rounded end. The unci 
are large, thin, roughly triangular lamellae with a single, super¬ 
posed tooth, strongly clubbed, and terminating in an acute point; 
a diagonal reinforcing rib crosses the uncus to the external dor¬ 
sal angle, where there is a rudimentary second tooth. The ven¬ 
tral branch of the manubrium is nearly crescent-shaped and about 
half the length of the median branch, which is very slightly de- 
curved. The dorsal branch is fairly long and curves strongly in¬ 
wards in order to give additional support to the dorsal wall of 
the mastax. 
The epipharynx consists of no less than four separate pieces; 
the principal pair are approximately straight, thin lamellae with 
a reinforcing rib at the anterior edge and expanded at the oral 
end into a roughly subsquare plate. The second pair are elongate, 
nearly parallel-sided, and rounded at the ends; they are twisted 
throughout their length, so that the ends lie nearly in the same 
plane. 
The oesophagus is long and slender. The gastric glands are 
remarkable; inserted approximately in the normal positions on 
the anterior portion of the stomach they extend for nearly two 
thirds of the length of the abdomen as slightly tapering, sinuate 
tubes; their contents is a blood-red, opaque, granular plasma 
mass, in which the nuclei are not visible, probably on account of 
the lack of transparency. At the death of the animal the glands 
contract to about one third of their normal length. The stomach 
and intestine are normal. Bladder and foot glands are very 
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