THE PHILIPPINE 
JOURNAL OF SCIENCE 
VOL. 20 : MAY, 1922 No. 5 
JANETOSPHAERA, A NEW GENUS, AND TWO NEW 
SPECIES OF VOLVOX 
By WALTER R. SHAW 
Of the Department of Botany, College of Liberal Arts, University of the 
Philippines, Manila 
FIVE PLATES AND FIVE TEXT FIGURES 
CONTENTS 
Introduction. Volvox rousseleti West. 
Janetosphaera genus novum. Volvox merrilli species novum. 
Janetosphaera aurea (Ehrenberg) . Volvox barberi species novum. 
comb. nov. A comparison of the species of Volvom. 
Volvoz Linnaeus. A key to the species of Volvoz. 
Volvox globator (L.) Ehrenberg. Species excluded from Volvoz. 
Volvox perglobator Powers. 
INTRODUCTION 
_ There have been recognized, hitherto, four species of Volvox 
that have their cells connected by protoplasmic strands. “Two 
of these, V. globator (L.) Ehrenberg and V. aureus Ehrenberg, 
have long been known, and have been the subjects of detailed 
study by several investigators, chiefly in Europe, with results 
which were summarized in the papers of Klein (’89A and ’90) 
and of Janet (’12). The two others have been described more 
recently; V. perglobator Powers (’08) from North America 
and V. rousseleti West (’10 and ’18) from Africa. 
The two older species are readily distinguishable from one 
another by the form of the vegetative cells and by the character 
of the outer wall of the oospore. Volvox awreus has cells which 
are round in surface view and connected by protoplasmic fila- 
ments as slender as the cilia, and the outer wall of the oospore 
185588 ATT 
