Mineralogy and Geology. 407 
order Kionocrania of the true Lacertilia; but the author had not been 
able to make sure that it possesses a columella. He also remarked that 
the possession by Telerpeton Elginense of vertebrae with concave articular 
faces does not interfere with this view, as although most recent Lacertilia 
have concavo-convex vertebra, biconcave vertebree much more deeply 
excavated than those of 7. Hlginense are met with among the existing 
eckos. 
Professor Huxley in conclusion drew attention to the interesting fact 
ve : D 
dated Paris, Dec. 6, 1866.)—Taltalite of Domeyko,* recently described 
by Mr. David Forbes,t comes from a copper mine of Sefior Moreno near 
Taltal, in the desert of Atacama, where it is associated with atacamite 
and copper glance. It occurs in large masses, fibrous, silky in luster, 
brownish-black in color, and has a dark gray powder. Domeyko obtained 
Si Al Fe Mg (Ca u cl 
20°8 16-2 11°3 08 24 44-5 07 2°25 == 98°95 
affording the oxygen ratio for the bases and silica 21°83 : 11-08. 
n a close examination of the mineral I have found that it is only a 
mixture of fibrous tourmaline and oxyd of copper. Treated with chlor- 
hydric acid, it leaves a residue which contains boracic acid, and has 
Besides, if from Domeyko’s results we take all the oxyd of copper which 
the acid takes up, we obtain for the remainder— 
Siss7 1301 feor2 Mgi49 Ou44l H41= 100. 
These numbers agree with those of a very ferriferous tourmaline, except- 
ing the absence of boracic acid which Domeyko did not detect. I have 
in my collection a specimen of blackish-brown fibrous tourmaline from 
Chili, which is free from oxyd of copper. lvat has been called taltalite 
(From a letter to one of the editors, dated Washington, April 18th, 
mens not i 
tained, since the publication of my former paper on this subject, that 
Spirifer propinquus Hall, and S. Hannibalensis Swallow, both nearly 
* Domeyko’s Mineralogy, 2d edit,, p. 139, 1860. + Phil. Mag, [4], xxv, 111. 
