NEW AVIAN TAPEWORM. 217 



siiggestinsf the genns Onchcrr'istica *. Of M. rostellaium Fuhiniinnn 

 writes t tliat each egg is siirroiiii(led by " uiie parenchyine va.ciin- 

 laire qui forme des cellules liexagoiiales." This is repre- 

 sented in a figure wliieh suggests a definite limiting membrane to 

 each of these "cellules," and thus separating them from the 

 general medullary parenchyma. In ;!/. cai/ennevse, M. secundum, 

 and M. macracanthu,in the same author + finds the same singly 

 imbedded ripe ova. And this condition appears to charactei'ise 

 some other s})ecies of the genus Monopylidium.. There is, 

 however, another sy)ecies of tapewoi-m recently described from 

 Gallintda chloropus under the name of " T(p.ma marchcdi " by 

 Mola §, which Fuhrmann || i-efers to the genus Monopi/Uddimi, in 

 which the dispositicm of the ripe ov.a is rather different. Mola, 

 in fact, ligiu'es the ova as not scattered singly through the paren- 

 chyma, but arranged in groups of one to six. Furthermore, he 

 does not represent the parenchyma surrounding them as vacuolar 

 (as does Fuhrmann in his species), but as distinctly fibrous. The 

 state of affaiis is therefoie obviously much more like that of the 

 species with which I am concerned in the present paper. Mola, 

 however, does not show any tendency for the fibrous parenchyma 

 to enwrap the bundles of eggs such as I have desci'ibed above in 

 Otiditcmiia. There is, furthermore, no suggestion given of an 

 epithelial lining to the cavities which lodge the eggs in 

 M. inarch(di. 



Some important histological details are added l)y Clerc 51 with 

 reference to Monopylidium infundibulwm. 



In this species we have, as it would apjiear, an agreement with 

 M. marchcdi in the fact that several ova are lodged together in 

 one lacuniform cavity of the medullary parenchyma. But these 

 cavities are not isolated ; they foi-m a complicated and irregula,r 

 network of lacuna?**. Later still, however, the individual ova 

 become more completely separated the one from the other, and 

 the typicai (?) character of the genus Monopylidium. is arrived at. 

 It may also possibly be the case with M. marchali. I have, how- 

 ever, no reason to suppose that the metamoi'phosis of the uterus 

 in my genus OtidiUenia proceeds any further than is indicated in 



* Cf., e.g., Beddard, P. Z. S. 1911, p. 633, text-fi^. 150, e. 



t Rev. Zool. Suisse, t. xvi., 1908. 



X Ceiitvalbl. f. Bakt. Pavasit. Rd. 45, 1907. 



§ Bull. Ac. Belg. 1907, p. 886. 



!l Die Cestoden der Vogel, Zool. Jahvb. 1908, Suppl.-]5d. x. 



^ Rev. Zool. Suisse, t. xi. 1903, p. 354. Ransom places this species in the genus 

 ChoanoUenia on the grounds ot his own observations as well as those of Colin (Nova 

 Acta Ac. Nat. Cur. Bd. Ixxix., 1901), which seem to sliow that the uterus is per- 

 sistent "and possesses an irregularly lolmlated cavitj' incompletelj' subdivided by 

 infoldings from the wall." This is, according to Ransom, a character of CJioano- 

 tcenia, and contrasts with the breaking up of the uterus in Monopi/lidium, which I 

 have referred to above. I may point out, in support of Clerc, that Cohn's figure {loc. 

 cit. pi. 32. fig. 47) may well indicate an incompletely mature uterus, since he 

 represents in the same proglottid both ovaries and testes. In Otiditcenia, at anj' 

 rate, the ovaries and testes have disappeared when the uterus is fully mature. Cohn's 

 figui'e may correspond to a stage figured in text-figure 30 of the present memoir. 



** Loc". cit. vol. xi. figs. 73, 77, 85. 



