ROTATORIA OF THE UNITED STATES. 
81 
Family 7. SYNCHAlTADiE. 
SYNCHiETA Ehrenberg. 
19. S. stylata Wierzejski. 
Rather rare in the harbor of Put-in Bay, Lake Erie. Few in the swamp near the fish-hatchery 
on South Bass Island at times when the lake water has poured into the swamp. 
Lake St. Clair (Jennings, ’94). Lake Michigan, Round Lake, Pine Lake, and West Twin Lake, 
near Charlevoix, Mich. (Jennings, ’96). Sandusky Bay, Lake Erie (Kellicott, 97). Waters connected 
with the Illinois River at Havana, 111. (Hempel, ’98). 
S. pectinata Ehrenberg.— Pond near Bangor, Me. (J. C. S., ’83). Whitmore Lake, Washtenaw 
County, Mich. (Jennings, ’94). Sandusky Bay, Lake Erie (Kellicott, ’97). Waters connected with the 
Illinois River at Havana, 111. (Hempel, ’98). 
S. tremula Ehrenberg?— Doubtfully reported by Kellicott (’97) in marsh water in the neighbor- 
hood of Sandusky, Ohio. 
Family 8. TRIARTHRADiE. 
POLYARTHRA Ehrenberg. 
20. P. platyptera Ehrenberg. 
One of the commonest of the Rotatoria. Abundant in surface and bottom towiugs and in collec- 
tions of plants from the bottom of Lake Erie in the region of South Bass Island, and from East 
Harbor. Also in the two swamps on South Bass Island. 
Lake Erie (Vorce, ’82). Near Minneapolis, Minn. (Herrick, ’85). Shiawassee River at Corunna, 
Mich. (Kellicott, ’88). Lake St.Clair; Chippewa Lake, Mecosta County, Mich.; Whitmore Lake, 
Washtenaw County, Mich. (Jennings, ’94). Sandusky Bay, Lake Erie (Kellicott, ’96). Lake Michi- 
gan, Round Lake, Pine Lake, and West Twin Lake, near Charlevoix, Mich. (Jennings, ’96). Waters 
connected with the Illinois River at Havana, 111. (Hempel, ’98). 
P. platyptera var. euryptera Wierzejski. — Waters connected with the Illinois River at Havana, 111. 
(Hempel, ’98). 
Anartlira aptera Hood.— Waters connected with the Illinois River at Havana, 111. (Hempel, ’98). 
TRIARTHRA Ehrenberg. 
21. T. longiseta Ehrenberg. 
Swamp near United States fish-liatchery on South Bass Island. Few. 
Water from Lake Erie at Sandusky, Ohio (Kellicott, ’96). Waters connected with the Illinois 
River at Havana, 111. (Hempel, ’98). 
Pedetes saltator Gosse. — Waters connected with the Illinois River at Havana, 111. (Hempel, ’98). 
Family 9. HYDATINADiE. 
Hydatina senta Ehrenberg. — This large and interesting rotifer is said to lie common in Europe, but 
in all the waters which I have examined for rotifers in this country Hydatina has been conspicuously 
absent. But it has been reported by Kellicott (’88) from the Shiawassee River at Corunna, Mich., 
and by Hempel (’98) from waters connected with the Illinois River at Havana, 111. 
NOTOPS Hudson. 
22. N. clavulatus Ehrenberg. 
Numerous at tiifles in the swamp near the United States fish-hatchery on South Bass Island, in 
company with Trochosphcera solstitialis. Also in East Swamp. 
There seem to be no very exact figures of the ciliary apparatus of this species; for the sake of 
comparison with Notops pelagicus n. sp. (see the next) I have made a study of it and present herewith 
a figure (plate 15, fig. 10). The corona of Notops clavulatus consists of the following parts: A circle 
of large cilia extends around the circumference of the head, interrupted (if at all) only at the mouth 
on the ventral side. The ventral half of this crown of cilia approaches a semicircle in form, but 
laterally there is a notch on each side, and the dorsal half is much less regular. Within this outer 
coronal wreath are three large styligerous prominences surrounding the buccal funnel, corresponding 
with the three prominences of N. pelagicus, and doubtless also with those of N. brachionus. The dorsal 
one of the three prominences is smaller than in N. pelagicus, and bears six long styles sheathed at the 
base, of the sort described and figured by Hudson and Gosse as occurring in N. brachionus. The two 
F. C. 13. 1899—6 
