1897 | NOTES ON UROGLENA AMERICANA CALK IIt 
is due to this fact. According to Zacharias the cilia of U. volvox 
are more nearly of the same length, there are no vacuoles or oil 
globules, and the individual cells are elliptical or oblong, being 
invariably drawn out into a tapering point which is prolonged 
intoathread. Onthe other hand, U. Americana, as shown, contains 
no network of threads, and the individual cells are spherical in 
outline, not being prolonged in any way. The single chromato- 
phore seems to be common to both species. The method of 
reproduction in U. volvox has not been satisfactorily demonstra- 
ted and no comparison can be made; however, nothing has 
been observed thus far, that would make it improbable that the 
peculiar method of multiplication as described above for U. 
Americana does not exist in the original species. 
For convenience I append a somewhat modified description 
of this species as given by Calkins: 
UROGLENA AMERICANA Calkins, 23d Ann. Rep. Mass. State 
Board of Health, 1891.—Canobium: irregularly spherical, vary- 
ing greatly in shape and size, averaging 200-300; no periph- 
eral canals or internal network of threads; revolves slowly 
through the water by means of cilia of individual cells. Judividual 
cells: spherical or occasionally slightly elliptical, never pro- 
longed into an appendage at end towards center of colony; two 
cilia of unequal length, 15-20m and 2~4m respectively, the 
longer with decided undulatory motion; red spot at base of 
cilia and a single chromatophore, of a yellowish green color, 
usually occupying one side of the cell and clinging close to the 
wall; nucleus, non-contractile vacuoles, and numerous oil 
globules present. : 
Water supplies of Massachusetts and —— Septem- 
ber-June.* 
I desire to acknowledge my indebtedness to Professor 
Farlow for his interest and advice, also for the loan of valuable 
and necessary literature on the subject. | 
CAMBRIDGE, Mass. 
* Since the above went to press, Urs has en pate om Indiana by Mr. 
33 & 
; S. —- of Purdue U niversity, 2 widel 
