306 
In conclusion I desire to express my heartiest thanks to Mr. 
B. B. Woodward, F. L. S. &c.. who has been good enough to re- 
vise my manuscript and help me over some linguistic difficulties. 
The microscope employed was Carl Zeiss I a, with the Abbé 
Camera lucida for wliich I am indebted to the Carlsbergfond 
in Copenhagen. 
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