NEW TAPEWORMS PROM THE HYRAX. 603 



to delicate muscles which retract the cirrus. The latter was 

 relatively wide and short and the sperm-duct within the cirrus 

 sac not coiled. The protruded male copulatory organ reminded 

 one rather of the penis of Anoplotcenia * than of a cirrus, for it 

 was wider at the free end than just within the cirrus sac. 



It is evident that this genus presents many resemblances 

 to the genera Zschohkeella and Inermicapsifer f. It agrees with 

 those genera in the following assemblage of characters : — The head 

 is unarmed and the excretory tubules form a plexus, or at least a 

 coil, at the very extremity of the rostellum, as in the species which 

 has just been described ; the segments are narrow and the genital 

 pores are unilateral. The excretory tubules furthermore form a 

 plexus within the medullary parenchyma throughout the body. 

 The ovary lies to the pore side of the segments and is distinctly 

 not a double organ ; the vagina dilates into a wide receptaculum 

 seminis. The cirrus sac, moreover, is small as contrasted with that 

 of many other tapeworms. On the other hand, there are certain 

 characters which argue against this placing of the worm whose 

 anatomy has just been described. These are as follows : — The 

 sperm-duct in our species is short and almost immediately dilates 

 into a large and long seminal vesicle, a state of affairs which is not 

 met with in the species of Inerr)iicapsifer known at present. 

 Finally, the network formed by the vasa efferentia is a feature 

 hitherto unknown in the genus Zschohkeella, though it occurs in 

 Inermicapsifer. Inasmuch as a reticular disposition of the vasa 

 efferentia is not necessarily diagnostic of a given genus as far as 

 we know, for it occurs in Chapmannia lapica and Hymenolepis 

 reticulata and not in other (at any rate in some other) species of that 

 genvis, this fact alone would not perhaps necessitate the removal 

 of the present species from the genus Zschokheella to which other 

 important characters would appear to assign it. But there is a 

 negative character which may be of very great importance. In 

 neither of the two individuals which I have studied was there the 

 least trace of the formation of the characteristic " egg-capsules," 

 which I prefer for reasons already given to call paruterine 

 organs. 



In all the species of Zschohkeella and Inermicapsifer examined 

 from this point of view, the formation of these capsules began 

 perhaps rather far back in the body, but still a long way before 

 the actual termination. Now both examples of the present genus 

 in my possession ended posteriorly in a few segments which 

 were rather longer than those preceding them and at the same 

 time rather narrower, suggesting, in fact, the end of the body. 

 They were, moreover, thicker than unripe segments. If this be 

 not the completely mature end of the body, the worm would be 

 very exceptional in the deferring of the egg-reservoirs to a point 

 so very far behind the scolex. Besides, two specimens selected at 



* See Beddard, P. Z. S. 1911, p. 1015, text-fig. 215. 

 t For the generic distinctions see below, p. 607. 



40* 



