Harring & Myers-—Rotifer Fauna of Wisconsin — II. 529 
tegument is very flexible and the outline changes according to the 
contractions of the animaL The body is very transparent. 
The transverse folds limiting the head and neck segments are 
unusually deep. The head segment is broadest anteriorly and 
tapers towards the neck; its width is but little less than the width 
of the abdomen. The neck segment is a little narrower than the 
head, but approximately the same length, slightly more than half 
the width. The abdomen increases very slightly in width for about 
half its length and then tapers gradually to the base of the foot; 
the tail is represented by a very slight dorsal elevation. The two 
short foot joints continue the outline of the abdomen without any 
sudden reduction in width. The two toes are very long and slender, 
slightly decurved and incurved; they have a nearly hemispherical, 
slightly compressed, bulbous enlargement at the base. The length 
of the toes is about one seventh of the total length. 
The corona extends down on the ventral side about one fourth 
of the length of the body; the post-oral portion projects as a 
minute chin. The unciliated apical plate is strongly convex; the 
buccal field has a well marked, troughlike median depression in 
which the mouth is located. The marginal cilia are short except 
on two lateral, auricle-like areas. 
The dorsal antenna is a short, stubby boss with a central depres¬ 
sion, at the center of which is a tuft of sensory setae. The lateral 
antennae have not been observed. 
The mastax is virgate and resembles closely the type of the 
genus, but in the development of the unci it is a little nearer the 
normal Notommata-type, The fulcrum is extremely broad at the 
base and tapers somewhat abruptly to a slender, rodlike, slightly 
incurved posterior section. The rami are broadly triangular and 
nearly symmetrical; their inner edges are provided with short, 
close-set, needle-like teeth, beginning near the base and continuing 
to the apex. The unci have a subsquare basal plate with a well 
developed ventral tooth, clubbed at the tip, and a rudimentary 
second tooth, beginning near the base of the ventral tooth and 
crossing the basal plate diagonally to its dorsal edge. Two short 
and very slender accessory teeth are attached to the ventral edge 
of the principal tooth in each uncus. The basal plate of the manu¬ 
brium is large and subsquare; the posterior portion is fairly stout 
and decurved at the tip. Two slender, slightly curved rods are 
imbedded in the walls of the mastax below the posterior edges of 
