NEW CESTODES FROM THE TASMANIAN DEVIL. 695 



the only one of these genera to which it bears any likeness in the 

 i^eprocl active system, and from this genus the characters of the 

 scolex at once distinguish DasyiiroUenia. Indeed, its inclusion 

 among the Tetracotylea ( = Tfenioidea) is not, to my mind, an 

 obvious certainty. In any case the hooked suckers exclude it 

 from the family Anoplocephalidte, to which nearly all the 

 Marsupial tapeworms belong up to the present. 



The most salient points of anatomical interest in this woi-m 

 appear to me to be the following : — 



(1) The immense size, relatively speaking, of the scolex and the 

 small size in comparison with it of the suckers. The fact that 

 two suckers are armed with hooks while the other two suckers 

 ai"e not so armed. 



(2) The great thickness of the longitudinal muscles, which 

 consist of at least four layers of bundles each containing very 

 many individual fibres of considerable stoutness. 



(3) The existence for the most part of only a single Avater 

 vascular tube on each side of the body, which is, moreover, in the 

 posterior segments completely divided up into a series of com- 

 partments, one to each segment, and whose lumen is also here and 

 more anteriorly divided by delicate septa jutting into its cavity. 

 Furthermore, by the fact that these tubes are not connected 

 in successive segments by transverse vessels, as is so nearly 

 universally the case. 



(4) As a remarkable structural feature, which is at present 

 mysterious in nature, may be mentioned the isolated cavities iw 

 the medullary region of the head which have no connection with 

 the water vascular tubes. 



(5) An anatomical feature of some importance is the very 

 variable relation to each other in position of the extremities of 

 the male and female ducts, which is correlated with an oi'ifice 

 upon one side of the body only. An alternation in the position 

 of the external pore may, we know, be accompanied with difference 

 in the relative position of the ducts as, for example, in the double 

 series of genital tubes of Moniezia. 



(6) In view of the very considerable peculiarities of structure 

 briefly indicated in the foregoing resume, it may be worth men- 

 tioning, as a remai'kable fact, that the generative organs do not 

 show any marked features of interest as compared with those of 

 other tapeworms. 



