PLATE X. 



Fig. 1. — Tli(> foutrast in this i)hoto.i?i';ii)li is more nearly what it should he, 

 tli()u;;rli the ha( k.s^round is in general too hri.uht. Some well-defined examples of 

 hriglit liy(lr(),i:('n Uocculi may he seen to the west of the si)ot, where small si)ots 

 were develoiiin^' at the time. 



Vh,. 2. — Tlie contrast here is rather too j?reat, and for this reason the hack- 

 i^round apju-ars too dark. The general character of the hright oaleiiim Hoccnli 

 is nevertlK'less fairly well shown. The hright tongue extending into the small 

 si)ot on the left is eruptive in character, and corresponds with the briglit hydro- 

 gen Hocculus referred to in the description of fig. 1. 



155 



