No.417.] MWORTH-AMERICAN INVERTEBRATES. 739 
long styles and a number of styligerous prominences ; at the sides 
of the corona two in ciliated auricles, which may be retracted. 
Asingleeye . . - + . Synchata 
dr. The slender foot one-third to one-half the length of the 
remainder of the body ; toes minute . . . . 82, S. stylata 
Wierzejski (Fig. 59) 
d2. Foot very short (less than one-sixth the length of the rest of 
the body) 
er. Body a swollen cone ; corona strongly convex, with two 
central thick, club-shaped prominences ; auricles very long, 
usually inclined backward . . . . 83, S. pectinata Ehr. 
e2. Body a slender cone ; coronal surface almost flat, without 
club-shaped prominences ; auricles small . 84, S. tremula 
Ehr. (Fig. 60) 
c2. Corona large, nearly transverse (slightly oblique), surrounded 
by a wreath of cilia which is interrupted ventrally, and bearing a 
number (3-7) of large prominences crowned with styles ; mouth 
near the ventral side of the corona 
di. Eyes two; jaws forcipate ; foot slender, of three joints ; 
stomach with six long cecal projections . . . 85, ZvipAylus 
lacustris Ehr. (Fig. 61) 
d2. Eyes one or none 
er. Eye one ; body long conical, humped dorsally, its outline 
with Pus distinct curves ; corona with three styligerous 
prominences. Ciliary wreath encircling the corona and a 
sub-square space at right angles to the corona on the ventral 
surface . . . . . . 86, Cyrtonia tuba Ehr. (Fig. 62) 
e2. No eye; body long conical ; a large rotifer, 87, Hydatina 
senta Ehr. (Fig. 63) 
€3. Body large, sac-shaped, hyaline (like an Asplanchna), foot 
very small and retractile, situated at the posterior ventral 
angle of the body, almost on the ventral surface. Jaws mal- 
leate ; eye single . . 88, JVotops clavulatus Ehr. (Fig. 64) 
*4. Body strongly arched dorsally; nearly flat ventrally ; 
cuticula thickened into a number of definite but inconspicu- 
ous folds or teeth (so that the animal might almost be con- 
sidered loricate); foot continuing the body axis, but nearer 
the ventral side, with two small retractile toes ; one eye 
. 89, Motops pelagicus uet (Fig. 65) 
45. Body almost square in ventral view ; foot one-third of 
total length, MS a continuation of the «hs axis; one 
Notops brachionus Ehr. 
4. Corona miho prominences d. styles ; consisting of an 
oblique (or even ventral) disk or area covered with close-set cilia 
or with numerous interrupted ciliary curves. Two lateral evertible 
