=n ea 
L.M.B.C. TURBELLARIA. 149 
larian fauna of the several districts. With the brilliant 
exception of Claparéde’s paper, the observations are fre- 
quently too fragmentary to allow us to accurately determine 
the species that are mentioned. A very valuable addition, 
therefore, to our knowledge is the description of 34 marine 
forms obtained by Professor von Graff during a two 
months stay at the “Ark” Millport, N.B. This lst 
incorporated in his ‘‘ Monograph” of the group (1882) 
furnishes a basis of comparison with other part of our 
coasts. For the last ten years, however, little work has 
been done on British Marine Turbellaria. 
We may next consider how and where marine Turbel- 
laria are to be found. Dividing the group for our present 
purposes into the flat leaf-lke Polyclads 1 cm. or so long, 
and the small, usually cylindrical Rhabdocels rarely more 
than 2 mm. in length, the followig methods have proved 
successful. The Polyclads are to be found: by extremely 
careful search on the under surface of weed-covered stones 
between tide-marks. Almost all forms are coloured in 
such a way as to remain unobserved unless the keenest 
vigilance be exercised. Infra-littoral species occur among 
shells, polyzoa and hydroids dredged at various depths up 
to 20 fms. The Rhabdocceles being minute cannot be 
directly observed on the shore. It is necessary to collect 
sea-weeds, stones covered with diatoms, ascidians, &c., 
the sand at the base of corallines, and to place these sep- 
_ arately in vessels containing sea-water. The Turbellaria 
will presently emerge and can be found by searching the 
sides of the vessel with a hand-lens. Dredge-material 
treated in ke fashion will yield numerous forms constitu- 
ting a fauna fairly distinct from the lttoral one. For 
Polyclads I have found the coast near Port St. Mary to 
be the best. For Rhabdocceles, the Calf Sound and tide- 
pools round Port Erin have proved most productive, 
