494 
Philippine Journal of Science 
1919 
are on the outside. They pass through the mouth of the bowl 
(the phialopore) just before closure occurs and form at first 
a close cluster within the embryo. Then, as the closed body 
slowly expands, the gonidia migrate forward from the region 
of the phialopore to take positions distributed within and near 
the wall of the coenobial cavity. For the genus of which the 
migratory habit of the gonidia is one of the distinctive characters 
I now propose the name Campbellosphaera, dedicating it to Douglas 
Houghton Campbell, whose life has been devoted to research on 
the life histories of plants as a basis for natural classification. 
In the material from which the type specimen has been 
selected the asexual specimens are more or less ellipsoidal and 
the gonidial numbers vary from eight downward. The gonidia 
in each coenobium usually vary in size and are largest near the 
posterior pole and smallest farthest from that pole. As a rule 
the larger gonidia segment first and the successively smaller 
ones later, inversely in the order of their size. In other large- 
gonidiate species of this family when some gonidia are regularly 
unlike the others it is the posterior pair or quartette that are 
the smaller and segment last. As a mark of distinction from 
such, this species will be described under the name C. obversa gen. 
et sp. nov., the specific name having reference to the reversed 
arrangement of the gonidia as compared with other types of 
Volvocaceae. 
Associated with the reversed arrangement of the gonidia, this 
species presents another character which may well be an addi- 
tional distinguishing character of the genus. I have observed 
that the daughters nearer the posterior pole mature earlier and 
are born earlier than the others, and that all the daughters are 
born through one opening formed in the posterior pole. Ac- 
cording to my observations on closely related genera, in all of 
them each daughter is born through a separate opening in the 
wall of the mother coenobium. 
In 1896 Meyer, in Germany, described a species under the 
name Volvox tertius. It is nearer to the genus about to be 
described than to either of the older species of Volvox. Un- 
fortunately Meyer gave no figures to show the general aspect of 
the coenobia, and it is impossible from his description and table 
of combinations of progeny to form, at this time, a conclusive 
opinion as to the proper disposal of his species. The form of 
the somatic cells and their membranes as shown in Meyer’s 
text figures 5 to 7 is remarkably like that of the cells in the 
anterior part of the coenobium of C. obversa and different from 
