AVIAN CESTODES. 885 
where a large conical paruterine organ exists which is distinct 
from the surrounding medullary parenchyma. 
§ Systematic position of Otiditenia. 
I shall now reconsider the systematic position of Otiditenia in 
the light of the foregoing revision of certain facts in its anatomy. 
As to the hooks which would form so important a means of 
preliminary family identification, I am not yet certain whether 
they are or are not the typical Davaineid hooks. They may well 
be so; but as I have not been able to view them sideways in my 
preparations I am unable to be positive. They may prove to be 
like those of Oligorchis paucitesticulatus * for example. There is, 
however, no doubt that this genus is not in any case a near ally 
of Oligorchis or Hymenolepis, so that we may perhaps fairly 
assume that the hooks after all conform to the idea that Otidi- 
tenia is to be referred to the Davaineide. Of this family 
Mr. Ransom has lately? made a useful table of classification 
which is an extension quite up to the present date of the table 
in his revision of the Cyclophyllidea £. 
From the table in question it appears that Otiditenia will 
come nearest to Chapmania. The matter for immediate 
settlement is, therefore, whether the two genera are to be 
regarded as identical, in which case my name will obviously have 
to be dropped. It must be remembered, however, that this near 
alliance depends upon whether we are to look upon Otiditenia as 
possessing a paruterine organ ; otherwise (still considering it for 
other reasons to be a Davaineid) Otiditenia will be nearer to, or 
identical with, either Davainea or Ophryocotyle. As to Davainea, 
we may at once dismiss the idea of near affinity; for in that 
genus the ripe embryos are included in numerous separate 
paruterine sacs quite unlike the paruterine organs of Idiogenine. 
The knowledge of the genus Ophryocotyle mainly depends upon 
the descriptions of O. insignis of Lonnberg, the most recent 
of which is in a memoir by Fuhrmann §. This worm is to be 
at once distinguished from mine by the immense number of 
hooks, 2000, which are disposed in an undulating line round a 
particularly large rostellum:; furthermore, the uterus, which is 
slightly lobate in form, lies behind the ovary, while the testes 
are dorsal to as well as behind the ovary. Moreover, the uterus 
shows no tendency to break up; it is conceivable, however, that 
it might later, in view of the very late breaking up of the uterus 
in Otiditenia. Finally, Ophryocotyle is to be characterised by 
multiple rows of minute hooks upon a portion of the suckers. 
This latter character does not seem to be found in-Otiditenia. 
bE) 
* Fuhrmann in “‘Nordische Vogel-Cestcden aus dem Museum von Goteborg, 
Medd. Goteborg. Mus. Zool., Afd. i. p. 18, fig. 8. 
+ “ A New Cestode from an African Bustard,” Proc. U.S. Nat. Mus. xl. 1911, p. 637. 
t Bull. U.S. Nat. Mus. No. 69, 1909. 
§ Centralbl. f. Bakt. Paras. Bd. xlix. 1909, p. 94. 
