18 ARKIV FÖR ZOOLOGI. BAND 14. N:0 13. 



of counting them (compare what is said above). The dis- 

 tinction »pas d'uterus» for Stylochoides and »2 uterus» for 

 Cotylocera is not a difference in reality because what Hallez 

 calls »deux oviductes ventraux» (»qui se reunissent en un 

 oviduct commun» (==Eiergang) corresponds to what Zahonj'- 

 describes as two uteri. Zahony says (p. 5): »Der relative 

 weite Eiergang fiihrt nach seiner Gabelung in zwei sackförmige, 

 prall mit Eiern gefiillte Uteri, die ventral zuseiten der Pha- 

 ryngealtasche liegen». The position of these is the same, 

 to judge from the figures which Hallez and Zahony give, 

 but the so-called »oviductes ventraux» (!) are narrow, be- 

 cause they do not contain any eggs. 



In the table Hallez says, further, that Stylochoides bas 

 »23 ovaires» and Cotylocera »ovaires peu nombreux». First, 

 I cannot believe that a certain number and such a figure as 

 23(!), is constant for the species, secondly Zahony says »die 

 Ovarien sind nicht sehr zahlreich». 



The last note in Hallez's table that Cotylocera bas one 

 »vésicule des glandes granuleux» and Stylochoides possesses 

 one »vésicule accessoire» should really indicate a difference 

 between these two genera, but as I have pointed out else- 

 where (1913, 1. c.) it is very probable that a mistake in this 

 respect occurs in Zahony's description. It may be mentioned 

 that I have a true Stylochoides from the same district in 

 which Zahony's specimen was taken. Consequently I have 

 in 1913 identified Stylochoides albus, Cotylocera Michaelseni 

 and Nuchenceros orcadensis as the same species. The dis- 

 cussion of the above-mentioned table shows that Hallez's 

 examination has not been sufficiently critical. 



It remains now to compare Chromoplana with these 

 genera which Hallez includes in this sub-family LaidlawUnce. 

 As the male copulatory apparatus in those genera is very 

 unlike that of Chromoplana and all the more as the pharynx 

 is tubular I think that at present we have no sufficient 

 reason for joining Chromoplana with them. The common 

 features which can be found do not prove any very close 

 relationship, asthey might have been acquired independently : 

 — The shape and size of the body, the absence of marginal 

 tentacles (the Prostiostomidoe also lack tentacles), the few 

 non-anastomosing gut-branches, the large size of the ovaries 

 and the consequent small number of them. 



