ROTATORIA OF THE OKOBOJI REGION 
277 
fairly abundant in kettle hole (7), and in Hottes lake (18) ; a few in- 
dividuals found in water from Gar lakes (15) and from Eittle Spirit 
lake (19). 
Mytilina ventralis brevispina (Ehrenberg) (Plate VI, Fig. 57). Four 
specimens were found among weeds in a small pond along the canal . (2). 
Buchlanis dilatato) Ehrenberg (Plate VI, Fig. 38). Found abundantly 
in the canal (2), fish ponds (16), and Hottes lake (18). 
Buchlanis pyriformis Gosse (Plate VI, Fig. 39). Several individuals 
of this species were found in water from the entrance of the canal (2) ; 
a few were found in Eittle Spirit lake (19). 
Buchlanis triquetra (Ehrenberg) (Plate VI, Fig. 40). By far the com- 
monest of the three representatives of the genus in the region, being 
found abundantly in Eake Okoboji (1), in kettle hole (7), in Green 
slough (12), and in the fish ponds (16) ; a few individuals were found 
in Gar lakes (IS) and in Sunken lake (17) ; one was found in water 
from Hottes lake (18), and one in water from Eittle Spirit lake (19). 
Dipleuchlanis propatula (Gosse) (Plate VI, Fig. 41). Two individuals 
were found in water from a marshy kettle hole near West Okoboji (10). 
Lecane gissensis (Eckstein) (Plate VI, Fig. 42). One individual was 
found in a tow near the mouth of the canal (2). 
Lecane luna (Muller) (Plate VI, Fig. 43). Quite common. Found in 
the canal (2), kettle hole (8), a pond near West Okoboji (10), fish 
ponds (16), Hottes lake (18), Eittle Spirit lake (19), Marble lake (20), 
and Eittle Sioux river (21). A few specimens were taken from Eake 
Okoboji (1), but the species is not common there. 
Monostyla acus Harring (Plate VI, Fig. 44). Several individuals were 
found in water from the fish ponds (16). 
Monostyla hnlla Gosse (Plate VI, Fig. 45). Very common. Collected 
from the canal (2), the sand-bar pond (3), kettle hole (7), kettle hole 
at West Okoboji (10), Gull Point kettle hole (11), Green slough (12), 
Gar lakes (15), fish ponds (16), Sunken lake (17), and Marble lake (20). 
The species was found several times attached in considerable numbers 
to the outside of the aquatic worm, Stylaria lacustris; in such cases, it 
attaches itself to the body of the worrq by means of its toe. 
Monostyla cornuta (Muller) (Plate VI, Fig. 46). This is a small 
Monostyla, not very common here. It was found in a kettle hole at 
West Okoboji (10), and again in Hottes lake (18). 
Monostyla crenata Harring (Plate VI, Fig. 47). Two specimens were 
found in a tow from Eake Okoboji (1), near the laboratory dock. 
Motwstyla lunaris Ehrenberg (Plate VI, Fig. 48). This species was 
found in the canal (2), kettle hole (5), a swamp near West Okoboji (10), 
and Hottes lake (18). The body in some specimens appeared clear and 
hyaline, and in others had a brick-red coloration. 
Monostyla quadridentata Ehrenberg (Plate VI, Fig. 49). Rather com- 
mon in this region, being found in Eake Okoboji (1), the canal (2), 
the sand-bar pond (3), and kettle hole (7). 
Lepadella acuminata (Ehrenberg) (Plate VI, Fig. 50). This species 
was found in a jar of algae which had been brought into the laboratory 
from the canal (2). It was collected also from a swamp near West 
Okoboji (10). 
