21,1 Shaw: Merrillosphaera 107 
spermatozoids was described as “vermicular from their extreme 
plasticity.” The antheridial coenobia were liberated after the 
spermatozoids had been formed, but before they had become 
separated. 
Oogonia were observed to be present instead of gonidia in 
two, three, or even all, of the eight daughters in asexual coe- 
nobia. In such female daughters the oogonidia numbered from 
thirty to fifty and were scattered indiscriminately over the 
posterior three-fourths of their respective coenobia. The oogo- 
nidia were two or three times the size of the somatic cells and 
of a light greenish color, while the daughters remained within 
the parent. They became still more enlarged and of a deep 
dark green color a short time after the daughters had been 
liberated. 
After fertilization the oospores became surrounded by a 
thickened spore wall, which appeared to be “slightly wavy in 
its outline.” The spore wall shown in his fig. 7 a (Plate 8, fig. 47) 
depicting one of these spores is characterized by Stein (’78, p. 
134) and by Klein (’89A, p. 196) as being slightly toothed. 
The diameter of the oospores was given as about 40 p, and the 
drawing of it measures about 42 yp. 
MERRILLOSPHAERA CARTERI VAR, WEISMANNIA (POWERS) COMB. NOV. 
Powers’s description (’08, pp. 152 to 162, 172 to 175) under 
the name Volvox weismannia of material collected by Professor 
Wolcott at Rocheport, Missouri, will now be recast for the pur- 
pose of comparison. The data will be taken from his photo- 
micrographic figures when they are not supplied by his text. 
It is to be noted that Powers wrongly called the gonidia ova. 
The form of the adult coenobium is obviously, from the figures, 
Spherical, or nearly so. The largest nearly mature asexual 
coenobium (his fig. 46) measure about 664 by 672 », and two 
others of about the same maturity (his figs. 37 and 55) both 
measure about 580 by 605 ». The size of the coenobia at the 
time of segmentation of the gonidia is indicated by an 8- 
gonidiate coenobium (his fig. 86) in which the gonidia show 
a radial flattening which is the first sign of segmentation. It 
measures about 350 ». A 10-gonidiate coenobium (his fig. 39), 
with the gonidia not yet showing signs of dividing, measures 
about 400 ». No free sexual coenobia are shown. The size 
of the daughters before birth reaches, as appears in his fig. 
55, more than 190 », the gonidia measuring at that time more 
than 22 » in diameter. So far as can be seen in the figures, 
