350 Scientific Intelligence. 
The sample examined gave— 
Tin (by crucible assay), - - - - 
Topaz crystals easily separated by the process, - : 3:10. 
er topaz crystals, too small to be easily separated, - 1:00(f) 
Oxygen and impurities (by difference),  - - - 45:00 
- 50°90 
100-0 
The material used for the assay was very carefully averaged, by pul- 
verizing about 500 grams of the ore, after the topaz crystals had been 
separated. A correction was subsequently made in the result of the 
assay corresponding to the quantity of topaz removed. 
School of Mines, Columbia College, N. Y., Dec. 23. 
2. Note by F. B. Meek and A. H. Worthen in relation to a genus of 
them on p, 174 of the lust number of this Journal—aAt the time we pro- 
posed the name Zrisocrinus for this genus, we were not aware that M. 
Koninck had described it under the name Philocrinus in 1863, among 
iques Recueillis dans €, p. 21. Liege, 1863). Owing to the fact that 
r. Koninck’s figure, (probably from’ the wearing of the stone from 
wever. 
exactly in its generic characters with his. This being the case, we 
and arrange our species, which differ 
specifically from that described by him, under his name. In doing this 
it also becomes necessary to change one of our specific names (Z. typus), 
It is worthy of note that Mr. Koninck’s figure of the arms and sec- 
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eneved to be derived from the vegetation of the period in which the 
shales were deposited. 
Similar black shales were brought to light by Dr. Houghton, beget 
years ago, in the lower peninsula of Michigan ; and the opinion was && 
pressed by him and by Mr. Hubbard, his assistant, that these shales were 
