388 
The Schizogregarines 
Dogiel (1907) has described a Selenidium from the gut of Sipunculus 
nudus, which he places, not in the genus Selenidium, but in that of 
Schizocystis, as Schizocystis sipunculi. Dogiel’s parasite is very probably 
Fig. 7. Selenidiidae, described by Brasil and Fantham (1907), from the gut of Phasco- 
losomes (Phascolosoma vulgare and P. elongatuni). Original figures (H. B. F.), copied 
from drawings made with camera lucida. x 600 (except A which is x 300). 
A. Species (a), trophozoite, with few myonemes, elongate in form, and with 
rounded nucleus. 
B. Species (a), stumpy form, nucleus transversely ovoid. 
C. Species (/3), with many myonemes, slender trophozoite with rounded nucleus. 
D. Species (/3), stumpy form, with transversely ovoid nucleus. 
E. Species (/3), association of gametocytes. 
a species of Selenidium, it is certainly a member of the family Seleni¬ 
diidae, and is best termed, at present, Selenidium sipunculi. Dogiel’s 
account of schizogony therein is apparently inaccurate (see Brasil and 
Fantham, 1907). 
While working at Banyuls (Pyrenees Orientales) in the spring of 
this year (1908) I found similar Selenid parasites in the Terebellid, 
Polycirrus aurantiacus. 
