XV, 6 
Shaw: Campbellosphaera 
513 
not megalogonidia such as others have mistaken for eggs. It 
is even questionable whether the connecting filaments shown in 
Klein’s fig. 7 (’89B, Plate 3) really belong there. The material 
is of a species more nearly akin to V. tertius and V. carteri than 
to V. aureus. 
A more completely described species is another by Powers 
(’07 and ’08), from Nebraska and other parts of North America, 
to which he gave the name V. spermatosphaera. i * * * This species 
also has rounded somatic protoplasts without protoplasmic con- 
nections, and the number of the cells has a range like that of 
Campbetlosphaera. But the dimensions of the coenobia run to 
much larger sizes, the cells being farther apart. The gonidia, 
or primary sex cells, are of considerable size in the daughters 
at the time of birth, though not so large as to indicate their 
differentiation at such an early period as is characteristic of 
Campbetlosphaera and the kindred rnegalogonidiate Volvoceae. 
The species is characterized by having male coenobia of which 
all the cells become antheridia (sperm platelets), leaving no 
somatic cells. 
0 
In my Philippine material there is still another species, ap- 
parently most nearly related to V. spermatosphaera, awaiting 
its turn to be described. 5 It is like the foregoing species in 
many respects, except that the gonidia are smaller at birth, 
and the antheridia are relatively fewer and formed in the same 
coenobia as the oogonia. 
A recent addition to the free-celled larger Volvoceae is one 
described by Powers (’07) from material obtained in Nebraska, 
and named by Shaw (’16) who proposed it as the type of a new 
genus under the name of Besseyosphaera powersi. This species 
is more like a Pleodorina i Shaw (’94) than like a Volvox, the 
gonidia not being differentiated in the daughters until after 
birth of the coenobia in which they are formed. The life history 
of Pleoclorina calif ornica has been rounded out by Chatton (’ll) 
from the study of material collected in France. A step farther 
down the scale is the species P. illinoisensis Kofoid (’98), the 
simplest of the Volvoceae which have differentiation of repro- 
ductive from somatic cells. The life history of this species has 
been given in detail by Merton (’08) from material obtained in 
Germany. 
1 Originally spelled “spermatosphara,” and emended by West (T6). 
5 The manuscript of the description of this species is partially prepared 
and the species assigned to be the type of a proposed new genus under 
the name Copelandosphaera dissipatrix Shaw. 
