4 H. B. FANTHAM. 
was fortunately able to obtain a few oysters infected with 
Spirocheta (Trypanosoma) balbianii, Certes. The 
parasite occurred in the crystalline style, and those parts of 
the gut more especially around it, namely, the stomach, 
intestinal ceecum, and anterior part of the intestine proper. 
These researches were begun in the famous marine labora- 
tory of Roscoff, Brittany, which I visited at the kind 
suggestion of Professor Minchin and through the courtesy of 
Professor Delage, of the Sorbonne. At this laboratory I was 
enabled to study this most interesting Protist at first hand. 
I would take this opportunity of returning my best thanks to 
Professor Delage and the staff of the laboratory at Roscoft 
for their kindness and attention, also for their hospitality in 
the form of free rooms while working there. To M. Fred 
Vlés, Préparateur du Laboratoire, I am especially indebted, 
as it is owing to his researches on Lamellibranchs that 
oysters, some of which proved to be infected with Spiro- 
cheetes, were introduced into the laboratory at Roscoff, having 
been obtained from Abervrach. 
The research on this and allied organisms has been con- 
tinued since in London on infected material procured after 
much difficulty. 
In an appendix to a paper by Prowazek, published in 1906, 
Keysselitz (4) notified the occurrence of a new Spirochete 
(S. anodontez) from Anodonta mutabilis. His descrip- 
tion is somewhat meagre, and the dimensions of the parasite 
are not given. Anodonta mutabilis is not a British 
species. After dissecting specimens of Anodonta cygnea, 
the well-known British fresh-water mussel, from different 
localities, I was able to announce! the occurrence of a 
Spirochete therein, probably the 8S. anodonte of Keysselitz, 
for it possesses pointed ends, as stated by him; and I am 
able to supply details of its movements and structure. I 
have much pleasure in thanking Mr. O. H. Latter, of 
Charterhouse, Godalming, for specimens of A. cygnea con- 
taining these Spirochetes, and for his excellent account of 
' «Proc. Zool. Soc.’ May 7th, 1907. 
