The absence of septa on the disc of Entobdella either developed 

 very recently or it is a primary phenomenon because there are no traces 

 or remnants of septa that can be discovered on whole mounts or on serial 

 sections of these worms. Besides this the disc of Entobdella shows other 

 peculiarities which distinguish this genus from all of the Capsalidae 

 mentioned before. Thus, in the present genus the fringe of the disc, which 

 in Capsalinae, Megalocotylinae and Trochopodinae has a festoon-shaped 

 appearance (see Figs. 1, 28, and 279)^, is represented as a very waving 



_ 



Certain authors sometimes represent it as complete (see for instance: 

 Goto, 1894; Johnston, 1937; Yamaguti, 1940, and others.) This is 

 undoubtedly erroneous. 



uninterrupted band, the folds of which sonnetimes simulate festoons but do 

 not correspond to them (see Fig. 281, A). Further, the fact that among 

 all Entobdella the disc is somewhat elongated and has peculiar, rather 

 characteristic outlines which are apparent in the corresponding drawings 

 deserves mention. In such a fashion the "facteur" (general appearance or 

 outline, nobis) of the disc, if one may so express it, slightly differs even 

 on superficial examination from the present and other tristomids. Not less 

 important also is the structure of the anterior end which lacks a sucker but 

 has very strong glandular "margins" with a slightly concave ventral (interior) 

 surface. These formations lie on a distinctly delimited section which can 

 be designated as a cephalic lobe. However, this lobe is not identical to the 

 cephalic lobe of the preceding groups, which corresponds only to its middle 

 part and which has a completely different nature (see Fig. 282). 



Fig. 282. Entobdella hippoglossi 

 (Oken), cephalic "lobe" of an adult 

 worm. On the left on the drawing 

 is seen the opening of the excretory 

 system and on the right the sex 

 aperture. (The left aperture of the 

 excretory system is not visible. ) 



In connection with everything 

 that has been said above, the unifi- 

 cation of Entobdella, Benedenia, and 

 Pseudobenedenia is not justifiable 

 and as a result of this we have to 

 exclude the first genus and place it 

 into an independent subfamily. 



455 



