MAMMALIAN CESTODES. 571 



Monticelli places the vagina in front of the cirrus-sac as I have 

 found it in D'qylopylklium. But this tapeworm has a cirrus 

 which is armed with spines which I have not found, and which 

 also does not seem to occur in C'otugnia. Nor does Monticelli 

 say anything of the eggs : which makes any comparison more 

 difficult. The segments, however, are more elongated than in 

 Gotugnia and thus like those of Dijjlojyylidium. 



Passing by the family Amabiliidas, of which the type-genus 

 Amahilia has double reproductive organs, and to which Diplo- 

 2yyliclium does not, as it appears to me, show any affinities, we 

 come to the Hymenolepidse. To this family, and especially to the 

 subfamily Dipylidiinfe (in the sense of Ransom), Diplopylidhmy 

 shows points of likeness. In this subfamily there are two genera, 

 viz. Dipylidmm and Fancerina, which have reduplicated gene- 

 rative organs. After the description of a Dipylidium, which I 

 have given in the present paper, I do not think it necessary to 

 emphasize further the distinctness of Dipylidh.mn and Diplo- 

 jjylidiuin. As to Pancerina, that genus has no hooks'^ upon the 

 rostellum ; it may be merely an Oochoristica with double gene- 

 rative organs, or, as I have suggested elsewhere *, an Ichthyo- 

 taeniid. Our knowledge of its anatomy is at present insufficient 

 to place it with accuracy. 



But although Dijylopylklmin is certainly not identical with 

 DipylidAtcvi, it agrees with that genus and some other Dipylidiinse 

 in the characteis of the egg-holding spaces (which I do not term 

 uterus for reasons given above) t. It is obviously quite near in 

 this respect to the species of Dipylidium which I describe in the 

 present paper. Oochoristica also has the ripe ova scattered at 

 random through the medullary parenchyma %. Monopylidium has 

 also the same type of egg-holding cavities which I have referred 

 to more at length above in describing this part of the generative 

 system of Biplopylidiimi. Furthermore, in Monopylidium there 

 are species (e. g. M. macracanihum §) where the hooks are not 

 very numerous (22) and arranged in two circles. On the whole, 

 I am inclined to place my genus in the near neighbourhood of 

 Dipylidium and Monojjylidium. 



* P. Z. S. 1913, p. 6. 



t Svpra, p. 567 etc. 



X Cf. e. cj. Beddard, P. Z. S. 1911, p. 633, text-fig. 150 e. 



§ Fulirmann, Centralbl. f. Bakt. u. Paras, xlv. 



