46 ]\lr. H. A. Bajlis <?w a neio 



Davaiiiea. Finding that it bore a close general reseniblancn 

 to the two species described as Davainen Yiolycaheohi and 

 ]). celehensis by v. Janicki (1901) — two forms wliich also 

 inliabit species of Mus, — I was almost led into the somewhat 

 natural error of placing my species near to them. A closer 

 examination, however, failed to reveal any traces of hooks on 

 tiie suckers ; and since I have carefully examined the scolices 

 of five individuals, having in one case teased np the suckers 

 in glycerine, and still failed to see any hooks, I think it may 

 be assumed that they are normally absent, and that this is 

 not merely a case of their accidental loss. This being so, my 

 specimens could not be referred to Davainea. 



Having come to this conclusion, and having made reference 

 to Dr. Ransom's very useful key to the genera of Ta3nioid 

 Cestodes (1909), the oidy genus there mentioned, I think, to 

 which this form can be assigned is Zschokkeella. In some 

 points which I shall mention it diverges slightly from this 

 genus as diagnosed by Ransom (loc. cil. p. 65), but it is 

 questionable whether the differences are large enough to 

 warrant the addition of another new genus to the ever- 

 growing list. 



The only other genus to which this species makes a near 

 approach is one very closely related to Zschokkeella, and 

 which has been described since the compilation of the key 

 referred to, viz. Inertnicapsifer , v. Janicki. It does, indeed, 

 bear a very close resemblance, not only in general aspect, 

 but in many details, to some of the sjiecies described under 

 this name by v. Janicki (1910) and by Bischoff (1912, 1913). 

 But the form to which it seemed nearest, Inerniicapsifer 

 hi/racis, v. Janicki, has been removed by Beddard into the 

 genus Zschokkeella (1912, p. 606). Dr. Beddard has also 

 now referred liis species Thysanotcenia gamhiana (1911 a 

 and h) to Zschokkeella. This form occurred in the Gambian 

 Pouched Rat (^Cricetomys fjamhianus) , so that, if my species 

 belongs to that genus, it will be the second occurring in a 

 rodent. 



On referring to Dr. Beddard's paper on Iiienuicapsifer and 

 the allied genera (1912), and turning to the useful key given 

 at the end of that ])aper, I came to tiie conclusion that 

 my species was considerably nearer to Zkchokkeella than to 

 Inermieapsifer as there diagnosed, if not actually (as I ven- 

 ture to make it provisionally) a member of the former genus. 



The special features which these two genera possess in 

 common are: — 



(1) An excretory system which forms a capillary network 

 in every segment. 



