O80 [Aucusr, 
pure sulphate with seven equivalents of water crystallized right rhombic, and 
had the form, appearance, taste, and. gave all the reactions of epsom salt. It 
gave me 50.8 per cent. of water, and 35.5 per cent. of sulphuric acid, which also 
prove that I had sulphate of magnesia. The analysis of the mineral is, accord- 
ing to J. L. Smith: 
H Si Al Fe Ca Mg K. 
J. L. Smith,... 20.66 45.66 4.87,-209 3.07 22.10 0.15—-98.45 
BE. Reakirt,.. < 19:96 44.07 AT NSTIOS BLS BNA) WoO  § al@lic 
ass FCiKKCsSCédN 
P. Keyser, 44.66 "7.79 26.60 0.12 0.16 
According to these analyses the mineral is Saponite. 
As the original communication appeared in your Journal, Tivhinks it proper to 
forward the above.”? 
Mr. Girard exhibited colored drawings of two species of the genus 
Saliuo, referring one to 8. erythrogaster, De Kay, and the other he con- 
siders as undescribed. 
“Its large scales and fusiform body would undoubtedly recall to mind the 
salmon, but on a more close examination the general shape and outline 
are far more elegant than in the salmon, preserving altogether better pro- 
portions between the different regions of the body. ‘The head forms about 
a fourth of the entire length, whilst in the salmon it is about the sixth only. 
‘The eyes are of medium size, and subcircular in shape, their diameter being co..- 
tained about seven times in the length of the head. The posterior half of the 
maxillary which is regularly and most decidedly curved downwards, gives to 
the shape of the mouth quite a peculiar aspect. The anterior margin of the dor- 
sal fin is equidistant between the tip of the snout and the base of the caudal. ‘The 
posterior margin of the latter is regularly crescent-shaped. The adipose is 
elongated, club-shaped, and situated opposite the posterior half of the anal. The 
ventrals are inserted under the middle of the dorsal, somewhat nearer the anal 
than the pectorals. The scales are remarkably larees contrasting greatly when 
compared to those of S. erythrogaster, S. fontinalis, and S. zamayeu. itd or amethys- 
tus. There are about a hundred and fifteen of them in the lateral line. 
The color in the female is uniform silvery grey, darker on the back and head. 
Subquadrangular or subcireular black spots are observed upon the sides of the 
head, behind the eyes, along the back, and the half of the flanks, also on the dor- 
sa] and caudal fins, to nearly their edge. In the male these same colors exist, 
but spread all over with a reddish tint, more intense on the flanks and beneeth 
than upon the head, back, and dorsal and caudal fins, where the red is sometimes 
but faintly indicated. ‘The name of Salmo sebago is proposed for this species, 
which inhabits the southern part of the State of Maine. 
Mr. Girard, referring to a communication made to the Academy some 
weeks since by Prof. Agassiz, on the subject of Crawfishes, remarked : 
Previous to the publication of his ¢¢ Revision of the North American Astaci,” 
&c., he was well acquainted with the fact that the genus Astacws proper, as now 
understood by Prof. A., was represented in North America. He further knew 
that this fact was demonstrated by Prof. J. D. Dana, in a paper published pp. 
10—28, of vol. vi. (Jan. 1852), of the Proceedings of the Academy, and that con- 
sequently Prof. Agassiz had no claim upon that discov ery. 
As to the circumstance that Cambarus Gambelii may be referred to Astacus on 
the ground of having eighteen branchia instead of seventeen, Mr. G. said he was 
* The sesquioxide of iron and alumina contain a trace of Silica, which was not 
separated. ‘ 
