CRUSTACEANS. 



47 



Tlio oliIcM- aiinlysPs of the sliclls of crustiiccans uro more or less iinsatisfaftory, but they all 

 agree as to tlic plio.sphalic cliarader of these oi-ganisins. C Scliiiiidt,-"' for o.\ainj)le, gives three 

 analyses, as follows: 



1. Axlnctvi fliiiiatilis; fresh-water crawfish. 53.27 per cent, inorganic. 



2. liobstcr; probably either Ilomanui viilynris or I'atinurus. 77.()(i percent inoriianic. 



3. Squillii miiiilis: anlirimp. :!7. 17 per cent inorganic. 



Schiincir.i ntiali/ses nf cruslncmns. 



The figures given here are for the inorganic matter alone. Schmidt mentions magnesium 

 phosphate as present but gives no determinations of it. 



Two analyses of crustacean shells b}' E. Frcmy *" are also worth citing: 



1. " Langouste " ; Pnlinurus vulgaris. 



2. "Ecrevisse"; probably the crawfish, ytstacusy/MrmfiKs. 



Fremy's analyses of crustaceans. 



Here, again, the determination of magnesia has been neglected. If we reject the organic 

 matter, the percentages of calciutn phosphate in the inorganic part of the shells become 12.03 

 and 10.55, respectively. 



Astacusfluviatilis seems to have received more attention from chemists than any other crus- 

 tacean. H. Weiske " found in fresh shells 4.97 to 5.31 per cent of calcium phosphate and in 

 old shells, partly cast off, 9.16 to 9.21 per cent. In " Krebsteine, " the concretions found in the 

 shells, the percentages ran from 10.73 to 11. 2S per cent. The total inorganic matter varied 

 between 61 and 67 per cent. 



Astacus has also been studied by Agnes Kelly," who also analyzed a myriapod, Julus 

 {lulus). Her figures are as follows: 



Analyses by Agnes Kelly. 



» Schmidt, C, .\nnalen Chemie u. Ptiarm., vol. 54, p. 3ffi, 184.i. 



«i Frcmy, E., Amiales chimie et phys., 3d ser., vol.43, p. 94, ls.i5. Frcmy also gives many analyses of vorlebrato bones, both recent and fossil. 



*i Weiske, H., Landwirthschaftliehe Versuclisstatioiicn, vol. 2(), |). 4.'), 1877. 



<- Kelly, Agnes, Jenaisches Zeitsehr., vol. 35, p. 429, 1901 



106135—22 4 



