494 Philippine Journal of Science "»i» 



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 



