DrAGRAm illustrating Prof. Herdman’s conclusions as to the 
life-history of the parasites. 
Species I. Vetrarhynchus unionifactor. 
B C 
? Globular cysts in 
Hornell’s free- liver and connective 
: K —_—-~}—__; “p ratow 
swimming Te tissues of Pearl-Oyster 
i (= Tylocephalum ludi- 
arva. 
7 pies ficans). 
if 
A ee This transition is 
/ \ doubted by Shipley. 
is yh \ 
/ \ D 
Kgg, Larval Tetrarhyn- 
mei hus wunionifactor in 
hatching in cee if era 
neighbourhood of ali- 
sea. mentary canal of Pearl- 
Oyster. 
F E 
Adult  Tetrarhyn- Immature = Tetr-a- 
chus unionifactor in rhynchus in Balistes. 
alimentary canal of Y  Thisstage is rejected by 
Rhinoptera javanica Shipley, and is regarded 
and  Ginglymostoma as collateral or acci- 
concolor. dental by Southwell. 
Species IT. “ Tetrarhynchus sp.” 
G 
Smaller globular cysts 
in connective tissues of 
Pearl-Oyster (= Tylo- 
cephalum minus). 
Southwell considers 
this the same species 
as “C” above. 

Ja 
Possibly the smaller 
Tetrarhynchus found 
in the intestine of the 
Pearl-Oyster, if it is 
distinct from T. unio- 
nifactor. 
/ 
y 
[30] 
