Flagellata and Primitive Algre. 81 
an interesting side-line of colonial development arising from a 
Pyramimonas -like type. 
Fig. 2. POLYBLEPHARIDACEjE.-—A, Polyblepharis singnlaris Dang. 
B, C, Pyramimonas delicatulus Griffiths : C, anterior view showing extremities 
of lobes of chromatophore. D, Chloraster gyrans Ehrb., showing stigma or 
“ eye spot.” E to L, Dunaliella salina (Dun.) Teodor.: E, vegetative cell, with 
bell shaped chromatophore, large nucleus, and reticulate protoplasm ; F, G, H, 
stages in division ; J, conjugation of zoogametes ; K, zygospore ; L, rupture 
of zygospore to set free the zoospores. M to P, Chlorodeudron lubricmn (Kuck.) 
Senn : M, a portion of a colony ; N, a single cell of same ; O, division of cell ; 
P, motile cell or zoogonidium. A from Dangeard ; B, C, from Griffiths ; D, 
from Stein; E and J, from Hamburger; F, G, H, K, L, from Teodoresco ; 
M to P, from Kuckuck. 
In setting forth a new classification of the Volvocales, Pascher 
(108) has adopted the suggestions made by Oltmanns as to the 
affinities between Carteria and Spondylovwrum, and by Schmidle 
as to those between Sphcerella and Stephanosphcera, and has separated 
these genera from the remaining Volvocales, dividing this order into 
the four families, Polyblepharidaceae, Carteriaceae, Sphaerellacete, 
and Chlamydomonadaceae. Wollenweber (153) has suggested that 
the Volvocine line shows progressive reduction in the number of 
flagella and of contractile vacuoles, hence Carteria and Sphcerella 
may be regarded as more primitive than the Chlamydomonads, the 
former in having four flagella and the latter in having numerous 
contractile vacuoles (as many as sixty in 5. Drcebakensis). It is, 
however, rather difficult to determine just which cytological 
characters should be regarded as relatively primitive and which as 
relatively advanced among the Volvocales. For instance, numerous 
