XV, 6 
Shaw: Campbellosphaera 
515 
still going. The appearance of the coenobia under the low 
powers, and the characters of the protoplasts, protoplasmic fila- 
ments and spores under the high powers, were so exactly like 
the excellent figures of Klein (’89 A and ’90) and of Overton 
(’89) as to engender in any one who studied the specimens with 
the literature a feeling that Vol voces must be about the same 
all over the world, and that both of the existing species have 
been well described. It was evident that the specimens would 
need remounting. Before demounting them, I took some notes 
and measurements — and fortunately, for the specimens after 
being remounted are not what they used to be. 
The most recent advance in our knowledge of Volvox has 
come from the studies of Janet (’12 and ’14) in France. In 
a long paper he gave a monographic account of the genus in 
which he incorporated and extended the membrane studies of 
Meyer, and he followed that with a preliminary paper in which 
he announced the discovery that the egg apparatus of Volvox 
globator is not a unicellular oogonium, but that it is multicellular 
and morphologically a dwarf coenobium. This fact will neces- 
sitate careful study of the corresponding parts of other species 
of Volvox and related genera. 
There are two well-marked groups of the higher Volvoceae: 
(1) those Volvox species with protoplasts connected by proto- 
plasmic filaments, namely, V. aureus, V. globator, V. perglobator, 
and V. rousseleti; and (2) those without the interprotoplastic 
connecting filaments, namely, V. spermatosphaera, V. tertius, 
V. af ricanus, and V. carteri (V. weismannia) . The species of 
the second group are more or less megalogonidiate, and it is 
those of this group that are more so with which Campbellos- 
phaera is more closely allied. My present conception of the 
relationships of the Volvoceae is represented by fig. 1. 
SUMMARY 
From fixed and living specimens collected near Manila, Phil- 
ippine Islands, a new species of the Volvocaceae (subfamily 
Volvoceae), is described which I propose for the type of a new 
genus under the name Campbellosphaera obversa. A type 
specimen is described in detail and figured by photomicrographs. 
It exhibits the most peculiar character of the genus, which is 
migration of gonidia, formed early in the development of the 
embryo, from the outside to the inside of the embryo through 
the phialopore. The gonidia become very large before dividing. 
The somatic protoplasts lack protoplasmic connecting fibers. 
