Miscellanies. » 875 
weathered shells of kindred species. The figure of the L. acuta rep- 
resents the columella as intruding upon the aperture, which is not the 
case with this shell. 
Cycias ELEGANS. C. testA bizonata, subglobosa, rhombico or- 
biculari, equilaterali, eleganter et tenuissime striata , natibus haud pro- 
minentibus; umbonibus tenuibus; infra albo-cerulescente. 
Remarks.—This shell is remarkable for its inflation, which contin- 
ues far over the disk of the shell, and terminates quite abruptly near 
the margin. The circumference very nearly resembles that of the 
C. calyculata, except that itis less curved below; that shell however 
is flattish and has prominentbeaks. C. rhomboidea, Say, approaches 
this in form, but is much less inflated between the umbo and margin, 
has very coarse strie and is destitute of the paler zones, which in 
this shell appear to be a constant character. ’ 
March 11, 1840.—Gxrorce B. Emerson, Esq., President, in the chair. 
Dr. SroreEr stated that he had received information from Dr. Kirt- 
land, of Ohio, that the descriptions and figures of the following fishes 
of the western waters, by the latter gentleman, had been completed : 
viz. Centrarchus hexacanthus; Polyodon folium; Catostomus Du- 
quesnii; C. melanops; C. gracilis; C. anisurus; C. elongatus; Hy- 
odon turgissus; Pimelodus cupressus ; P. limosus; P. ceeruleus; Ca- 
tostomus bubalus; C. nigrans; Chatoessus ellipticus; Lepisosteus 
oxyurus; L. platostomus; L. ferox; Leucioperca Americana ; Aci- 
penser nudus; A. macrostomus ; Anguilla lutea; Ammocoetes con- 
color; Labrax chrysops; Icthelis macrochira. 
A specimen of shell limestone from Machias, Me. presented for the 
cabinet by Lynde M. Walter, Esq-, was laid on the table. Dr C. 'T. 
Jackson stated that this was from the sandstone formation in Machi- 
as, Me., and was composed principally of univalve shells. It had 
been consolidated by the heat of the trap which had foreed its way 
through it, so that in some instances it had been converted into com- 
pact and even into crystalline limestone ; occasionally the limestone 
has been broken, by the intermixture of the trap, so as to form lime- 
stone breccia. ; 
‘March 18, 1840.—Tuomas A. GREENE, Esq. in the chair. 
communication from A. A. Hayes, 
Dr. M. Gay read the following 
Esq., of Roxbury, on the Native Nitrate of Soda, found in South Peru. 
The existence of beds of Nitrate o 
and the inhabitants of a most arid and desolate region, have 
known 
’ 
t article of commerce and 
made it by simple operations an importan 
manufacture. | 
