73 
provided with heavy muscular envelope in the proximal end of 
the prostatic vesicle. But it is to be noted that the orientation of 
the male apparatus is just the opposite in them. In Cestoplana it 
lies, as Lang particularly emphasizes, behind the male opening, 
demonstrating in this respect agreement with the Cotylean type and 
disagreement with the ordinary conditions among Acotylea. The 
presence of a kind of adhesive organ at the extreme end of the 
body in Cestoplana is then worthy of some attention. However, we 
lack information as to its structure. Lang, giving no details in this 
respect, says only: „Ich vermuthe, dass hier Klebzellen vorkommen“. 
Marking it first sn on Taf. 15, Fig. 1 (derived from „Saugnapf«), 
he has evidently later taken a more cautious standpoint, as in the 
explanation of the plate he used the term „Haftorgan“. How much 
it might resemble the sucker of the Cotyleans is yet unknown but 
supposedly not to any great degree. In itself the sucker is not of 
very great importance as proof for relationship, as such organs 
might be acquired independently, but in combination with other 
features it might be of value. But Cestoplana is of a rather in¬ 
different type. In the case of tentacles, a valuable characteristic 
in the Polyclads, there is no trace of such formations, neither 
nuchal as in Acotylea nor marginal as in Cotylea. The arrangement 
of the eyes hardly gives us points of appui and the same is more 
or less true in the other organization. 
Recently (1922) Frieda Meyer has described a Cestoplana 
polypora from the Red Sea. The most interesting feature in this 
Polyclad is undoubtedly the multiplication of the female apparatus. 
These organs occur behind one another in the median line of the 
body and their number vary from 5—30. Referring to my discus- 
sion on Polyposthia (1913), the authoress says: „Wenn Sixten Bock 
sagt, dass Multipla von Begattungsapparaten durch Spaltung eines 
einzigen Apparates zu erklåren ist. . . , warum soilte die gleiche 
Annahme nicht fiir den weiblichen Apparat giiltig sein. Sonst wurde 
ja bei den von mir untersuchten Tieren den weiblichen Geschlechts- 
apparat ganz fehlen**. In her paper is related a notice received 
in a letter from Dr. Stummer-Traunfels on a case of duplicity 
of female apparatus as well as of sucker in a specimen of Thysanozoon 
brochi. Both these data give the necessary support for a similar 
interpretation of the postgenital vesicles of Cryptocelis Ijimai Bock 
