420 



Scientific Intelligence. 





74. Cupellaecrinites inflatus, T. 



75. Haplocrinites hemisphericus, T. 



76. ovalis, T. 



77. granulatus, T. 



78 . maximius, T. 



79. Platrcrinites Ann Dixoni, T. 

 80. Hunts villa?, T. 



81. poly dactyl us, T. 



82. msculptus, T. 



*83. Donacierinites simplex, T. 

 *84. Da3monocritiites cornutus, T. 



Astylocr mites. 



*85. Crumenaecrinites ovalis, *T. 



*86. Agassizocrinites dactylifonnis, T. 



87. gracilis, T. 



*%$. Granatocrinites cidariformis, T. 



Those marked with * are new genera. 



We may confidently believe that the state will bring out the results 

 of the survey in the most liberal manner, with full illustrations. 



3. On the Altered Dolomites of the Island of Bate ; by James Bryce, 

 (Phil Mag., 1849, [3], xxxv, 81.) — Mr. Bryce describes examples of 

 magnesian limestone beds, intersected by dykes of greenstone. The 

 limestone is rendered saccharine in texture, having a crumbling char- 

 acter adjoining the dyke, but hard a short distance off. By analysis, 

 it was found that the unaltered rock contained 20 percent, of carbonate 

 of magnesia, while the part altered by the dyke contained only 1 to 3 

 per cent. The following are analyses made under the" direction of Dr. 

 Robert D. Thomson. 



• ■ - 



• • • 



1. Altered, 



2. 



3. 



4. 



u 



ii 



u 



Si and Al 

 691 

 5-70 

 hard 194 



0-28 



• • • 



• * 



• • 



Fe 



CaC 



1-68 



9065 



1-28 



91-08 



0*52 



96*48 



0-56 



96-58 



MgO 



1-00 

 Ml 



1-2:; 



2*24 



100-24 

 9923 



100-17 

 99-66 



5. 

 6. 



unaltered, . . . 970 



9-08 



• • • 



112 

 112 



67-42 

 6700 



17-31, H, 0, and coaly matter 445 

 18*06 M " 474 



100 

 100 



The material for the first two analyses was that nearest the dyke and 

 most altered. The author enquires, " To what cause are we to assign 

 the changes that have taken place? Has the magnesia been sublimed 

 by heat; or has it been withdrawn by the solvent power of free car- 

 bonic acid ?" " The subject is one of great interest both io the geolo- 

 gist and chemist, as the facts are directly opposed to the received 

 views, and as no instance of similar changes on dolomitic rocks has, so 

 far as I am aware, been put on record." 



Associated with the trap of the island of Bute, there are beds of lig- 

 nite, in some cases three feet thick, and consisting of hard, stony coal. 

 The lignite rests upon a tufa and is overlaid by an ochreous layer and 

 then by trap or greenstone. 



4. Plumbic Ochre from Mexico. — We have received from Prof. Bai- 

 ley of West Point, specimens of plumbic ochre, or native litharge, from 

 New Mexico. He writes concerning it 



New Mexico. He writes concerning it : — " It was given to me by fltaj' 

 Geo. Thomas, of U. S. Army, who got it in New Mexico, where he 

 said it was called 'silver flux,' and used in working silver ores. 





> 



many places in tne p. v *...^ v . vama 



tioned at Saltillo I saw some forty or fifty sacks of it which had been 



100 miles south 



taken from a mine near Mazapel, a mining town, s 



of Saltillo. I saw a few pieces which had been picked up by officers 

 in the streams between Ceralvo and .Monterey, and also in the Sabmas 



