540 Wisconsin Academy of Sciences, Arts, and Letters, 
yond the dorsal antenna; snbcerebral glands are not present. The 
eyespot is at the posterior end of the ganglion. 
Greatest length 680ja; body 210ft; right toe 470ft trophi 
Monommata grandis is abundant everywhere in weedy ponds in 
the United States; judging from published records it is not com¬ 
mon in Europe, but it is uncertain whether this is to be attributed 
to actual rarity or to reiterated assertions of its specific identity 
with M. longiseta. 
Subfamily TETRASIPHONINAE. 
Genus TETRASIPHON Ehrenberg. 
Notommatid rotifers with fusiform, illoricate body, without con¬ 
striction between head and abdomen; the tail is rudimentary; the 
foot is short and two-jointed, with two long, slender toes. 
The corona is an oblique, weakly ciliated area without auricles 
and used for carrying food to the mouth only, not for propulsion; 
the mouth is a little below the center of the corona. 
The antennae are long and tubular, the dorsal antenna double. 
The mastax is an aberrant form of the virgate type; the fulcrum 
is short and the rami very large and dome-shaped; the mallei are 
imperfectly developed. The epipharynx consists of four pieces 
of complicated form, which apparently serve to expand the mouth 
opening. The piston is very bulky, but weak; it is attached to 
the ventral floor of the mastax. 
The retrocerebral organ is well developed; the subcerebral glands 
are longer than the sac. The eyespot is at the posterior end of 
the ganglion. 
Type of the genus.—Tetrasiphon hydrocora Ehrenberg. 
Subfamily LINDIINAE. 
Genus LINDIA Dujardin. 
Notommatid rotifers with spindle-shaped, elongate, illoricate 
body, usually with several indistinct annulations, and without con¬ 
striction at the base of the foot, which has two very small toes; 
the cloaca opens under a small tail, at the base of the foot. 
The corona is an elongate, oval area covering the oblique anterior 
surface of the head and continuing beyond the mouth on the ven- 
