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Hidden and Mackintosh—Herderite Jrom Maine. 135 
Art. XIX.—On Herderite (2), a glucinum calcium phosphate and 
Jtuoride, from Oxford County, Maine; by WinLtaM EARL 
Hippen and Jamus B. MACKINTOSH. 
In the January number of this Journal, page 73, attention 
was called to the mineral ‘here described. Our specimens were 
obtained in October, 1883, from Mr. Nathan H. Perry, of South 
Paris, Me. They were then thought to be topaz, so much did 
they also occur on muscovite: some little albite (var. cleave- 
landite) is often associated with them. The average size of 
the crystals is about 3™™ diameter, though one of 1™ and 
another of nearly 2™, length and thickness was noticed. This 
last crystal was the only one which gave a hint of cleavage 
brachydome measured over O gave 113°. The observed planes 
are 0, I, 7-2 (?), three brachydomes, two macrodomes, three 
ctahedrons and two other octahedral planes beveling e 
edges between the regular octahedrons and the brachydomes.* _ 
* The best crystals which we have received have been placed in the hands of 
be E. 8, Dana for crystallographic determination, and his results will be 8 
eye in the next number of this Journal. He has given us the following dat : 
* publication here: The fundamental angles obtained are 1-1 1-4, over 0, 
