21,1 Shaw: Merrillosphaera 89 
mannia (Powers) comb. nov. Less fully described is 2 form col- 
lected and prepared by Migula, and called by Klein (’89B) 
Volvox aureus. This evidently is not the Volvox aureus Ehren- 
berg described by Klein (’89A and ’90) but is a new species 
similar to M. carteri which I call Merrillosphaera migulae sp. nov. 
Of another species of Volvoz, one described by West (’10 and 
18) under the name V. africanus, my Philippine material con- 
tains stages which fill out the life history and show its affinity 
with the species and varieties listed in the foregoing paragraph. 
It therefore becomes Merrillosphaera africana (West) comb. nov. 
(Volvox africanus West). 
A third species of Volvoxz, described by Meyer (’96) under 
the name JV. tertius, seems to fit into the new genus more readily 
than into any other, and this may be sufficient reason for clas- 
sifying it tentatively as Merrillosphaera tertia (Meyer) comb. nov. 
(Volvox tertius Meyer). Of this species we have as yet only 
Meyer’s description, which is in many respects very meager. 
All of these species are characterized by having rounded so- 
matic protoplasts without connecting filaments, and also by 
having gonidia which are differentiated at an early embryonic 
stage. To this extent they agree with Campbellosphaera, but 
they differ from the latter in lacking the migration of the gonidia 
through the phialopore into the coenobium. Two other species 
that lack interprotoplastic filaments develop their gonidia only 
after birth, and these I had previously assigned to two genera. 
Those with a reproductive area in which a small number of the 
cells develop into gonidia were put in the genus Besseyosphaera 
(Shaw, ’16), while those with a reproductive area in which all 
of the cells develop into gonidia were put in the genus Pleodorina 
(Shaw, 94). 
In presenting the descriptive details pertaining to the species 
and varieties of Merrillosphaera I shall begin with the descrip- 
tions of a series of specimens, selected primarily from those 
which have been photographed and that are supposed to represent 
the life history of M. carteri var. manilana, of which the first 
will constitute the type of the variety. Then the nearly related 
varieties of the literature will be taken up separately and 
described with the same terminology, for comparison with the 
variety in hand. 
In another paper I purpose to extend our knowledge of Mer- 
rilosphaera africana (West) Shaw by means of descriptions 
of specimens in my collections. 
