96 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Family 18. BRACHIONIDiE. 
BRACHIONUS Ehr. 
93. B. bakeri Ehrenberg. (Plate 22, figs. 45 and 46.) 
One of the commonest rotifers in East Harbor, Lake Erie, and in the swamps on South Bass 
Island. The animal varies exceedingly in the form of the lorica and in the development of the spines 
on the lorica. In small land-locked pools in the glacial markings on Starve Island, a form with very 
short spines (fig. 45) was abundant; in the swamps of South Bass Island the long spined variety 
(fig. 46) was found. The pools on Starve Island are subject to evaporation and frequent drying up 
by the sun ; possibly the different form found in these pools is due to the greater concentration of 
various salts in this water or to some kindred factor. B. bakeri is known to vary excessively (see 
Rousselet, ’976, for figures of the chief variations); it would probably be a favorable form for an 
experimental study of the causes of variation. It seems hardy, and can usually be procured in 
quantity, so that it could probably be cultivated under experimental conditions. 
Granville, Ohio (Herrick, ’85). Shiawassee River at Corunna, Mich. (Kellicott, ’88). Near Cin- 
cinnati, Ohio (Turner, ’92). Lake St. Clair and Chippewa Lake, Mecosta County, Mich. (Jennings, 
’94). Pool on shore of Pine Lake, and in West Twin Lake, near Charlevoix, Mich. (Jennings, ’96). 
Trenton, N. J. (Stokes, ’96«). Waters connected with Illinois River at Havana, 111. (Hempel, ’98). 
B. bakeri var. brevispinus. Waters connected with Illinois River at Havana, 111. (Hempel, ’98). 
94. B. militaris Ehrenberg. 
Very abundant in swampy parts of Lake Erie, in Portage River, Ohio, and in the swamps on 
South Bass Island. 
In Hemlock Lake, near Rochester, N. Y. (Attwood, ’81, under the name B. comum). Croton water, 
the New York water supply (Hitchcock, ’81, under the name B. conium Attwood). Minnesota (Herrick, 
’84, plate v, tig. 6, not named). “Common in the West” (Herrick, ’85). Creek on Grand Island and in 
Buffalo City Park (Kellicott, ’87, under the name B. conium Attwood). Shiawassee River at Corunna, 
Mich. (Kellicott, ’88, Tinder the name Noteus conium Attwood). Near Cincinnati, Ohio (Turner, ’92). 
Lake St. Clair (Jennings, ’94). Susan Lake and West Twin Lake, in north Michigan (Jennings, ’96). 
Sandusky Bay, Lake Erie (Kellicott, ’96). Water connected with the Illinois River at Havana, 111. 
(Hempel, ’98). 
B. pala Ehrenberg. — Near Minneapolis, Minn. ( J. W., ’83). Near Cincinnati, Ohio (Turner, ’92). 
Sandusky Bay, Lake Erie (Kellicott, ’97). Waters connected with the Illinois River at Havana, ill. 
(Hempel, ’98). 
B. urceolaris Ehrenberg. — -Near Cincinnati, Ohio (Turner, ’92). Waters connected with the Illinois 
River at Havana, 111. (Hempel, ’98). 
B. tuberculus Turner. — Near Cincinnati, Ohio (Turner, ’92). Sandusky Bay, Lake Erie; also found 
by C. C. Mellor at Newark, Ohio (Kellicott ’97). 
B. mollis Hempel. — Waters connected with the Illinois River at Havana, 111. (Hempel, ’96 and ’98). 
B. dorcas Gosse. — Waters connected with the Illinois River at Havana, 111. (Hempel, ’98). 
B. dorcas var. spinosus Wierz. — With the type (Hempel, ’98). 
B. punctatus Hempel. — Waters connected with the Illinois River at Havana, 111. (Hempel, ’96 and ’98). 
B.rubens Ehrenberg. — Shiawassee River at Corunna, Mich. (Kellicott, ’88). Waters connected 
with the Illinois River at Havana, 111. (Hempel, ’98). 
B. variabilis Hempel. — Waters connected with the Illinois River at Havana, 111. (Hempel, ’96 
and ’98). 
B. angularis Gosse. — Sandusky Bay, Lake Erie (Kellicott, ’97). Waters connected with the 
Illinois River at Havana, 111. (Hempel, ’98). 
B. angularis var. bidens Plate. — Waters connected with Illinois R. at Havana, 111. (Hempel, ’98). 
B. gleasoni Up de Graff.— Elmira, N. Y. (Up de Graff, ’82 and ’83). 
B. conium Attwood = B. militaris Ehr. 
B. intermedins Herrick (’85). — Insufficiently described for recognition. It seems probable from 
the points mentioned that the animal was Noteus quadricornis Ehr. Locality not given. 
Scliizocerca diversicornis Daday. — Waters connected with Illinois R. at Havana, 111. (Hempel, ’98). 
S. diversicornis var. homoceros Wierz. — With the type (Hempel, ’98). 
