886 DR. F. E, BEDDARD ON 
But in the case of these hooks upon the suckers, it would appear 
that in Chapmania they tend to drop off. This difference, 
therefore, between Otiditenia on the one hand, and_ both 
Ophr yocot yle and Chapmania on the other hand, must be held 
in reserve until more specimens have been examined. There is, 
however, I think, no doubt that Otiditenia is quite distinct from 
Ophryoc atyle, if only by reason of the characteristic rostellam of 
the latter. There now remains only the genus Chapmania. ‘The 
first obvious point of difference between the two supposed genera 
is the armature of the suckers in Chapmania; but, as alveady 
admitted, we cannot apparently dwell too strongly upon this, for 
the reason that these hooks are said to be occasionally shed from 
the suckers in Chapmania. I haye, however, examined the 
suckers in two specimens of Ofiditenia ; and the examination of 
two examples lends naturally further support to the view that 
the hooks are really missing. Apart from this, there are 
apparently two main points of difference which forbid a fusion of 
these genera. In Chapmania tapika—which species alone comes 
into comparison with Otiditenia, for Ch. taurika has unilateral 
generative pores and in other respects differs perhaps to a generic 
extent from its supposed congener—a tentacle arises from each 
sucker; this is figured by Furhmann as elongated and conical. 
I have found nothing of the kind in Jongitudinal and transverse 
sections of the scolex of Otiditenia. It may be urged that this 
failure to discover a similarity may be due to ‘the complete retrac- 
tion of the sucker tentacle, and thus to the difliculty of detecting 
it. This may be so; but in the meantime I have seen, in a 
tapeworm from Vumida (which may perhaps be the very species, 
Chapmania tapika), the tentacle freely moving about in the 
living worm. Having thus recognised the structure, it is of 
course less likely that I should miss it in examples where it was 
ravefully looked for. Besides, the apparent non-retraction of 
this tentacle in the preserved examples of Chapmania examined 
by Fubrmann, leads to the inference that it would be present in 
an unretracted condition in my spirit-preserved specimens of 
Otiditenia, were it a character of that species. The next point of 
difference is the paruterine organ. If we are to regard the 
modified medullary parenchyma in its entirety as the paruterine 
organ in Otiditenia, the corresponding organ of Chapmania 
as figured by Clerc * is distinctly different. 
Neither Fubrmann nor Clere gives much in the way of deserip- 
tion of the organ. Judging from the figure the paruterine organ 
of Chapmania only occupies about half of the ripe proglottid. 
It extends towards the uterus, which occupies about the other 
half, and ends on its side turned towards the uterus in a flat 
surface. ‘This is obviously totally different from the structure 
which I have figured in Otiditenia, and considered to be possibly 
a paruterine organ. On the other hand, the breadth of the 
* Centralbl. f. Bakt. u. Paras. Bd. xlii. 1906, p. 722. 
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