Magnification = 1000x Lenght = 30 & 48 µm.
Two common form of Raphoneis amphiceros Ehrenberg .
Acquisition from an heritage of a Tudor family in Wisconsin, USA.
These came from BlackRock near Brighton coast, UK
Slides was prepared in Nov. 1960.
Today we find Blackrock Yatchting and Brighton Yacht Brokerage
established on Brighton Marina Village, UK