KEPTILIAN TAPEWORMS. 27 



cuticular layer of large pear-shaped cells is deeper than in the 

 Ichthyotcenia from Varanus, and, like the layer in them, is very 

 conspicuous and deeply staining. Some way below this glandular 

 layer is a layer of stout longitudinal fibres, such as are figured 

 by Schwarz in species of Ichthyotcenia from Sei'pents, a layer 

 which I have been quite unable to find in such species from 

 Varanus as I have examined. This layer in the present species 

 is very conspicuous, and the differential staining of logwood 

 emphasises it very well. The layer is usually more than a single 

 fibre deep, but in places only a single fibre deep. The greatest 

 number of fibres which I have found in a dorso-ventral direction 

 is not more than four. The layer thus appears to be thicker 

 than in Ichthyotcenia nattereri and /. ccdmettei figured* by Schwarz. 

 The layer seems, as Schwarz has pointed out, to form the boundary 

 line between the cortical and medullary regions of the proglottids. 

 The latter author has directed attention to a peculiarity in the 

 disposition of the transverse fibres which differs from that of all 

 other tapeworms. He described aiid figured t these fibres as 

 lying within — i. e., not on — the boundary of the medullary paren- 

 chyma. I have myself observed in the present species many such 

 fibres in proglottids not fully mature. In fully mature proglottids 

 I have not detected them. They are irregular and certainly 

 occupy a good deal of the medullary region. They are not, how- 

 ever, by any means so plain as the longitudinal fibres just 

 described. 



The watei'-vcoscular tubes in the neck-region are plainly two on 

 each side. They show a character here which is at least not . 

 very common among Tapeworms. Both the tubes, which are 

 fairly accurately superposed, have distinctly thick walls and are 

 rather larger than usual. Moi-eover, the lumen is slit-like, the 

 tubes pi"esenting the appearance of being compressed dorso- 

 venti-ally ; there is no doubt that in the fully mature proglottids 

 only one of these tubes is present on each side of the body. 



The generative organs conform wuth the Ichthyotpeniid plan, but 

 show numerous dififerences in details from those of the other 

 species already considered in the present paper. The testes 

 present the usual arrangement, but are, perhaps, more strictly 

 confined to the lateral regions of the proglottid than in some 

 other species described in the present paper. When they are 

 fully ripe the testis seems to become entirely converted into a 

 mass of spermatozoa, which does not wholly fill the cavity in 

 which it lies. In transverse sections a series of these cavities are 

 seen to lie side by side, only separated by a thin strand of 

 medullary parenchyma. 



The vc(.s deferens forms the usual Ichthyotseniid coil, but seems 

 to be of less calibre than in the species of this genus from 

 Varanus. This coiled region extends to quite the middle of the 



* Loc. cit. Taf. i. fig. 4 and Taf. iii. fig. 10, Im. 

 t Loc. cit. Taf. iii. fig. 10, tvm. 



