xv, 6 Shaw: Campbellosphaera 511 
Outer wall of oospore reticulately wrinkled or ridged, diameter, 
about 34 to 42 p. Spermatozoids, about 6 p long. 
Habitat. — Fresh-water ponds, near Manila, Philippine Islands. 
COMPARISON WITH PREVIOUSLY DESCRIBED SPECIES 
The earliest described Volvox with megalogonidia similar to 
those of Campbellosphaera is Volvox carteri Stein (’78), which 
was described by Carter from Bombay, India, in 1859, under 
the name Volvox globator. Carter’s description presented the 
large gonidia, one of which is shown in his fig. 4. That these 
gonidia must be differentiated early in the ontogeny is evident 
from the size which they reach before birth as shown in his fig. 
1. Points of difference from Campbellosphaera appear in this 
figure ; namely, the globose form of the coenobia, and the practi- 
cally uniform size of the gonidia in each daughter. This uni- 
formity is further shown in his fig. 3, in which the gonidia have 
reached the maximum size before segmentation. Carter re- 
presented his species as having somatic cells with globose or 
ovoid protoplasts, in which respect it is like our new genus. 
A variety of Volvox carteri was described by Powers (’08), 
from Missouri, under the name Volvox weismannia. Powers 
failed to perceive that what Carter, in referring to his fig. 4, 
called a “daughter” was in reality a gonidium and identical with 
one of the reproductive cells which Powers called “primary sex 
cells” and “ova.” Powers did, however, clearly recognize and 
emphasize the fact that these reproductive cells are differentiated 
at an early stage in the development of the embryo. The semi- 
diagrammatic nature of Carter’s drawings masked the symmetry 
of the arrangement of the gonidia in the coenobia, which Powers 
noted as characteristic of his species. Powers supplied enough 
information on the embryos to show that the species lacks a 
migration of the gonidia such as is characteristic of Campbello- 
sphaera. He showed clearly that his species also forms “dwarf 
male” coenobia, a point of difference from C. obversa. He over- 
looked the distinction between asexual and female coenobia, 
though he figured embryos of both kinds [Powers (’08), Plate 
26, fig. 45 asexual, and fig. 47 female]. 
In my own collections, made in the neighborhood of Manila, 
on many of the eight hundred thirty-four slides of Volvox in 
my cabinets, and among the one hundred fifty photomicrographs 
of Volvox that I made in 1916, there is a multitude of forms 
and stages of Volvox carteri, which promises to afford material 
