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The geographical distribution of Stylochidae. 
In his valuable monograph on the Stylochines Meixner gives 
in a table the distribution of 20 species, recognized as belonging 
to this group. He comes to the conclusion that the Stylochines 
“fast iiber die ganze Erde verbreitet sind“. Although my family 
has a somewhat wider extension than Meixner’s group, I must re- 
gard it as having a more limited distribution. The main divergence 
in our opinions refers in the first place to the faet that I exelude 
them from the Arctic and Antarctic Seas. The reason why Meix¬ 
ner took his standpoint was very soon afterwards eliminated. He 
expressed it thus: “Sogar im siidlichen Polarmeer ist in jiingster 
Zeit eine Stylochus-Art, St. albas Hallez aufgefunden worden.“ In 
the later, more extensive description Hallez (1907) has shown that 
this species represented a new genus, related to the Euryleptids 
in Cotylea! At present no Stylochid is known south of 35^ S. Lat. 
In the Antarctic collections of Turbellarians from the Scottish, 
French, German, and Swedish South Polar-Expeditions, the family 
is unrepresented and also for other reasons I find it very unlikely 
that Stylochids really exist in Antartic waters. 
If we now turn to Meixner’s other presumption: “Wahrscheinlich 
werden auch die arktischen Meere Vertreter unser Subfamilie be- 
herbergen“, it might be mentioned that it has not yet received 
any further support. According to Verrill, the earlier supposed oc* 
currence of Stylochus littoralis Verrill at Newfoundland is of a very 
problematic nature, and that is also mentioned by Meixner himself. 
On the eastern coast of North America no other Stylochid is re- 
corded north of U. S. A. and in the Pacific not north of Vancouver. 
Though it is very likely that some species might extend its distri¬ 
bution further north, I cannot believe that any Stylochid is able 
to enter Arctic waters. 
As regards the European coast, we are entitled to draw a con¬ 
clusion from negative facts, as we have a more extensive know- 
ledge of the Polyclad fauna. It seems then quite improbable that 
Stylochids reach so far north as to the Scandinavian coast. In his 
“Catalogue des Turbellariés du Nord de la France de la cote Bou- 
lonnaise" Hallez does not mention any Stylochus-speciQS and an 
occurrence of this genus in British waters is unknown. If we then 
