BULLETIN OF THE BUSSEY INSTITUTION. ITT 
II. Dry shells of the common Crab (Lupa dicantha, Milne-Edwards) 
as picked up on the sea-shore near Wood’s Hole, Mass. This sample and 
all that follow were prepared for analysis by powdering and sifting the 
shells as in No. I. 
Ill. Dry shells of the Horse-shoe or King-Crab (Limulus Americanus) 
picked up on the sea-shore near Wood’s Hole. Shells from the backs and 
legs of several of the crabs were freed as completely as possible from ad- 
hering remnants of flesh, and were then ground to powder and sifted as 
in No. I. 
IV. Shells of the common Oyster (Ostrea Virginiana, Lister), obtained 
in the fresh condition at a Boston market. The shells were carefully 
cleaned, washed, and dried. A pound and a quarter of the air-dried 
shells were powdered and sifted in order to obtain a sample for analysis. 
_Y. Shells of the common Clam (Mya arenaria), obtained in the fresh 
condition from a fish-dealer in Cambridge. 
VI. Shells of the common Quahaug or Hard clam (Venus mercenaria) 
from Wood’s Hole, Mass. 
VII. Shells of the Broad Sea-clam or Hen-clam (Mactra gigantea) as 
picked up dead and blanched, upon the beach at Manchester, Mass. 
VIII. Shells of the common Small Mussel (Mytilus borealis, Lam.) 
from the sea-shore at Wood’s Hole. These shells had been washed clean 
by the sea-water i.c. they contained no trace of the animals to which they 
had belonged, but they were not blanched. 
IX. Shells of the Large or Horse-mussel (Mytilus modiolus, Turton) 
from the sea-shore at Wood’s Hole. Not a few of these shells were some- 
what worn and ‘‘ worm-eaten.’’ 
X. Shells of the common Scallop of Cape Cod (Pecten concentricus, 
Say), from Wood’s Hole. 
XI. Shells of the Sea-snail Natica heros from Wood’s Hole. 
As is well known, the incombustible portion of all such shells as 
have been mentioned above consists chiefly of carbonate of lime. 
This ingredient is common to all the shells, and they contain such an 
overwhelming proportion of it that, from the agricultural point of view, 
there would not be the least interest in determining the precise amount 
of this constituent in any one case. I have confined my inquiries there- 
fore to the estimation of the amounts of phosphoric acid, potash, and 
nitrogen as set forth in the following table, and in two or three cases 
the amount of magnesia also. 
VOL. II. 12 
