60 H. B. FANTHAM. 
These Spirochetes are gut parasites with a primitive 
habitat. The mode of infection of the Lamellibranchs by 
them seems to be a casual one, namely, by the mouth. 
15. The systematic position of the Spirochetes is difficult 
to determine. They have affinities both with the Bacteria 
and the Protozoa. They are undoubted Protists. Personally, 
I rather incline to the Protozoal nature of these organisms, 
and consider that a provisional new class of the Protozoa, 
namely, Spirochetacea, might be instituted for their 
reception when our knowledge of them is a little more 
extended. 
At this juncture it will be well to deal with one or two 
points relating to the Spirocheetes discussed in this memoir, 
but not, perhaps, directly concerned with the body of the 
paper. These have been left over purposely until the end, 
and will be considered in the form of Appendices. 
AppEnpD1x I. 
On Some Points in the Chemistry of the Crystalline 
Style of Anodonta cygnea. 
The functions of the crystalline style of Lamellibranchs 
have been much disputed. To discuss this question of func- 
tion is hardly within the purview of this Appendix, but I may 
state that Mitra (28) has, in my opinion, given by far the 
best account of this structure, though, perhaps, his meaning 
is not always clear. Mitra began a chemical investigation of 
the style in Anodonta cygnea. 
The substance of the crystalline style is incapable of 
diffusing through a membrane, and is proteid in nature. It 
is, therefore, a colloid. In order to determine its proteid 
nature the Xanthoproteic reaction was tried, and. a reddish- 
yellow coloration was obtained with concentrated nitric acid 
and ammonia. Confirmatory tests were Millon’s reaction 
(corrosive sublimate and nitric acid) producing a yellow pre- 
