PLATE CVII. 



FIGS. PAGE 



1-2. Xanthidium tetracentrotum Wolle. 1 ? after 



Wolle ( x 500) ; 2, x 520 . . 58 



3. X. tetracentrotum forma protuberans W. & (1. S. 



West. x 520 . . . 59 



4. X. tetracentrotum var. quadricornutum (Roy & 

 Biss.) W. & G. S. West. x 400 (after Roy 

 & Bissett) .... 59 



5-6. X. coiitmn-rxiuii W. & (I. S. West. 5, x 525; 



6, x 520 . . . . 59 



78. X. controversum var. planctonicum W. & Gr. S. 



West, x 520 . . . .60 



910. X. subhastiferum vav. 3Inrrai/i fovma triguetra 



W. & G.'S. West, x 430' 57 



