460 WILLIAM NICOLL. 
cincta,” but these words describe exactly the chief features 
which struck me when I removed my first specimens from 
the gall-bladder of their host. The thick, fleshy body 
extended vigorously towards both ends, the large knob-like 
ventral sucker (apertura dorsali), pale pink or fesh-like in 
colour and surrounded by a strikingly bright yellow ring 
contrasting strongly with the dull greenish hue of the rest of 
the body. These appearances are lost on preservation, and 
it was on this account, I believe, that Jacoby, who examined 
preserved material, was not impressed with Rathke’s descrip- 
tion. A most potent objection to the identification of Dist. 
anarrhichee with D. fellis is the difference in habitat, for 
Rathke’s specimens occurred in the stomach. Various hypo- 
theses might be advanced to meet this difficulty, but it makes 
no difference to the matter in hand, for, as Looss has 
explained, such names as D. anarrhiche lupi were not 
intended by Rudolphi as specific names, so that the name D. 
fellis Olsson remains good. 
With regard to Stafford’s specimens, the ovary is described 
on the left side and the testes as large and spherical. 
According to Jacoby’s observations, which I confirm, the 
ovary always lies on the right side and the testes are obliquely 
oval in Distomum fellis. This renders it doubtful if 
Stafford’s specimens are really identical with D. fellis, but 
it is possible that Stafford’s statements may be due to a slip 
of the pen. 
My adult specimens measure 2°5-3°3 mm. in length and 
1:1-1-6 mm. in breadth. The normal breadth seems therefore 
to be about half the length, but the animal is capable of 
considerable extension. In the contracted state the breadth 
may almost equal the length and the animal becomes nearly 
globular. ‘The shape in the quiescent state is most probably 
that represented by Jacoby. The body is thick and nearly 
opaque. 
Numerous immature specimens were found, and these 
measured 1:1-2°5 mm., so that in this species maturity is 
reached at a size of about 2°56 mm. 
