CESTODARIA 465 



the excretory system, cannot be considered of much weight 

 when the fmidamental resemblances I have indicated are taken 

 into consideration. I therefore propose, in order to emphasize 

 these fundamental resemblances, provisionally to unite the 

 Caryophyllaeidae with the Gyrocotylidae into one 

 Order, the P a r a 1 i n i d e a , in contradistinction to the 

 Amphilinidea, which contains only one known family,^ 

 the A m p h i 1 i n i d a e . 



The Paralinidea may be provisionally defined as 



Cestodaria («) with the three sexual apertures situated 

 close together ; (b) with the uterus and vagina running 

 parallel to each other in the same dorso-ventral plane 

 along the median longitudinal axis of the body ; (c) with 

 the testes restricted to the anterior end of the body ; 

 (d) with a bilobed ovary ; (e) without calcareous bodies ; 

 (/) with a reticulate excretory system ; (g) with a hexa- 

 canth larva (?). 



The Amphilinidea possess the opposite characters, viz. 



(a) the uterine and vaginal apertures are situated at 

 opposite ends of the body, the former being at the anterior 

 and the latter posterior ; (h) the uterus and vagina run 

 in opposite directions from the ovary, the former anteriorly 

 and the latter posteriorly ; (c) the testes extend, with the 

 uterus, over the greater length of the body ; (d) ovary 

 one-lobed : (e) calcareous corpuscles present ; (/) excretory 

 system consisting of two main lateral longitudinal channels 

 with minor regularly arranged looped vessels ; (g) with 

 a ten-hooked larva. 



Finally, it is evident that of the two Cestodarian Orders — 

 Amphilinidea and Paralinidea — the latter is much 

 more closely related to the C e s t o d a m e r o z o a than is the 

 former (Text-fig.). In both the Paralinidea and the 

 Bothriocephalidae the uterus and the vagina run 

 medianly in the same dorso-ventral plane, the vas deferens 

 opens from the anterior side of the proglottis (though the testes 



^ Benham (1 ) would place W a g e n e r i a in this Order, but this organism 

 is not yet known with sufficient accuracy to justify its inclusion in any 

 family. 



