Earring & Myers—Rotifer Fauna of Wisconsin — II. 541 
tral surface as a slightly projecting chin; the marginal cilia are 
relatively short, except on two latero-frontal areas provided with 
long and powerful cilia adapted to swimming, in the majority of 
species seated on evertile auricles; the apical plate is enclosed by 
the marginal ciliation and has occasionally a projecting rostrum; 
the mouth is near the center of the corona. 
The mastax is adapted to suction or ‘"pumping” by oscillating 
as a complete unit on a transverse axis near the posterior end 
of the fulcrum; the name “cardate” is proposed for this peculiar 
type. The fulcrum is short and narrow, usually tapering towards 
the posterior end; the rami are lyrate, resembling the forcipate 
type; the ventral branch or cell of the manubria is very large, 
equaling or exceeding in length the median or principal cell, with 
which it forms a rather acute angle; the unci are feebly developed, 
the teeth being rudimentary and usually united into a thin plate. 
Nearly all the species included have an epipharynx of very com¬ 
plicated form; it may consist of one, two or four separate pieces, 
which act as supports for the edges of the mouth, while the oscil¬ 
lation of the entire mastax produces behind it the vacuum neces¬ 
sary for the pumping action. Two salivary glands occupy the 
posterior portion of the mastax in some species. 
The retrocerebral organ consists of a rather small, hemispherical, 
ductless sac at the posterior end of the ganglion; it is filled with 
red pigment granules and encloses the large, disc-shaped eyespot, 
seated on the ganglion. 
Type of the genus.—Lindia torulosa Dujardin. 
Subfamily BIRGEINAE. 
Genus BIRGEA Harring and Myers. 
Notommatid rotifers with short, broad, illoricate, anteriorly 
truncate body; the head is short and very broad, separated from 
the abdomen by a slight constriction; the abdomen is ovate and 
ends posteriorly in a short, broad tail; the foot is long, very slender 
and three-jointed; the toes are fairly long and lanceolate. 
The corona is frontal with a circumapical band of short cilia, 
interrupted dorsally, and two lateral, auricle-like areas with long 
cilia adapted to propulsion; the buccal field is evenly ciliated and 
the mouth is near the ventral edge. 
