206 J. D. Whitney on Algerite and Apatite. 
The Devonian formations, which on the map are colored ina 
broad belt through New York and thence narrowing westward to - 
Cleveland and Sandusky, are there represented as cut off by the 
belt of lower carboniferous, before mentioned, which runs west- 
ward to the Illinois coal field. Now the fact is, that the forma- 
tions traced through southern New York and thence to Cleveland, 
are absolutely and unmistakeably continuous along the western 
margin of the great Alleghany coal field, through Ohio and Ken- 
tucky, and even into Tennessee and Alabama. 
’ Our author has recognized the formation about Richmond, Va. 
as Liasic. while the same formation in North Carolina is colored 
as New Red Sandstone. We do not discuss the question of the 
age of the New Red or Triassic of Connecticut Valley and*fur- 
ther south: we only say here that there is no reason whatever 
for regarding that of North Carolina as differing in age from that 
of the Richmond basin. 
There are other errors with regard to regions less known, 
as, for example, that of extending the cretaceous area to the east 
side of the Missouri for several hundred miles above Council. 
Bluffs; and-of terminating the same formation on the northwest 
more than a hundred miles short of its known limits. But these 
are excusable, compared with many points we have passed in 
review. . 
Arr. XX.—On the Chemical Composition of the minerals Al- 
gerite and Apatite; by J. D. Wuitne é 
1. Algerite. 
Iv the Journal of the Boston Natural History Society (vol. ¥), 
p. 118) an account of the analysis by T. S. Hunt of a supposed 
new mineral, to which he has given the name of Algerile, will 
be found. Another analysis of the same substance by Mr. R. 
Crossley has been published (see Am. Jour. Science, [2], x; 77): 
Having been furnished’ by F. Alger, Esq. with specimens of 
this mineral, I have made an examination and analysis of it, the 
results of which appear to be of interest in their relation to a0 
important branch of mineralogical chemistry, hitherto much neg- 
lected, but which has received a new impulse from the laborious 
and interesting researches of G. Bischof. 
The first light thrown upon the real nature of this supposed 
new mineral species, was by J. D. Dana, who was struck by the 
evident altered appearance of the specimens examined by him, 
and published the following remarks (Am. Jour. Sci. [2], ¥¥ 
440): “Lam satisfied that the form of the crystals is a sqva7e 
prism. In external appearance they would not be distinguished 
