84 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
TRIPHYLUS Hudson. 
24. T. lacustris Ehrenberg. 
This rare and interesting rotifer occurred abundantly in East Swamp, South Bass Island, both 
the male and the female being found. Western (’92) gives a figure of the male of this species. 
CYRTONIA Rousselet 
25. C. tuba Ehrenberg. 
East Swamp, South Bass Island, abundant. 
Trenton, N. J. (Stokes, ’97, under name Proales hyalina n. sp. ). 
Family 10. NOTOMMATADJE 
Albertia naidis Bousfield. 
Lake St. Clair (Jennings, ’91). 
It seems possible that the Anelcodiscus pellucidus described by Leidy (’51), from the intestine of 
Stxjlaria fossularis Leidy, in the neighborhood of Philadelphia, may have been a rotifer of this genus. 
TAPHROCAMPA Gosse. 
26. T. annulosa Gosse. (Plate 14, figs. 4, 5, and 6.) 
Swampy parts of East Harbor, Lake Erie; common. 
There is so much characteristic detail about the form and structure of this animal that is not 
brought out in the published figures, that I have thought it worth while to give some camera figures 
of specimens killed in extension. Fig. 4 gives a side view. The animal is here represented as curved 
more than other published figures show it, but in my experience this is about the form the living 
specimen usually has when moving along the bottom. On account of the fact that it is so curved, the 
entil e body can not well be shown in a single dorsal view. Fig. 6 gives a dorsal view of the anterior 
three-fourths of body, while fig. 5 gives a corresponding view of the posterior three-fourths, showing 
the toes, with the broad tail above them. In regard to the internal anatomy, it needs to be said 
that the intestine does not open in the broad dorsal de 2 )ression near the posterior end of the body, as 
Weber (’98) has represented it, but the opening lies just above the toes, beneath the tail. Mr. Gosse’s 
statement in the monograph that the opening of the intestine is beneath the two toes is equally incorrect. 
This is perfectly clear in mounted specimens. 
Shiawassee River at Corunna, Mich. (Kellicott, ’88). Lake St. Clair, and the following inland 
lakes of Michigan: McLaren Lake, Oceana County; Crooked Lake, Newaygo County; Chippewa 
Lake, Mecosta County (Jennings, ’94). Channel between Round and Pine Lakes, near Charlevoix, 
Mich. (Jennings, ’96). Waters connected with the Illinois River at Havana, 111. (Hempel, ’98). 
27. T. saundersias Gosse. 
Portage River, Ohio, among Utricularia. 
Shiawassee River at Corunna, Mich. (Kellicott, ’88). Lake St. Clair (Jennings, ’94). 
28. T. selenura Gosse. 
East Harbor, Lake Erie and swamp near fish-hatchery on South Bass Island. 
Lake St. Clair (Jennings, ’94). Trenton, N. J. (Stokes, 96«). 
T. clavigera Stokes. — Trenton, N. J. (Stokes, ’96 b). 
PLEUROTROCHA Ehr. 
29. F. parasitica n. sp. (Plate 16, figs. 13 and 14.) 
Parasitic on the annelid Xais lacustris, from among plants of the bottom of Lake Erie about 
South Bass Island. 
In waters connected with the Great Lakes I have several times noticed a Pleurotroclia attached 
by its jaws to tbe external surface of the small annelid Mats lacustris. The first one observed I 
thought I could identify with Ehrenberg’s P. constricta (Jennings, ’94, p. 14), but I have since been 
able to make a more careful study, with the result of showing that this identification is wrong, the 
body being much too short and broad. It resembles more nearly P. gibba Ehr., yet is clearly distin- 
guished from that species by the much greater size of the toes, as well as by the totally different form 
of the body and head. It resembles no other of the recently described species of this genus, so that 
it is necessary to describe it as a new species. Ventral and side views of the animal are shown in 
plate 16, figs. 13 and 14. 
