L46 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



rich supply of material, and for many useful hints as to 

 collecting and identifying my specimens. 



As to the occurrence of the species : the commonest 

 Rhabdocoele by far was Macrorhynchns croceus ; Monotus 

 Uneatus and M. fuscus coming next in number of indivi- 

 duals. The two latter, taken together, hardly outnumbered 

 the former, while to these three species belonged about 

 half of the Turbellarians I examined. Of the remaining 

 types the commonest were Pseudorhynchiis bifidus, Byrso- 

 phlebs intermedia, Promesostoma agile, Provortex balticus, 

 and Macrorhynclius heligolandicus. 



My experience of the Parasitic Rhabdocoeles is limited 

 to the new Graffilla, which occurred in numbers in the 

 kidney of almost every Buccinum undatum and Fitsnc 

 antiquus that I examined. The " Cocoons " of Fecampia 

 erythrocephala were not uncommon between tide-marks, 

 but I searched in vain for the worm itself. 



TUBBELLABIA. 

 I. TBICLADIDA. 



Poly cells nigra, 0. F. Midler. 



New to Isle of Man fauna. 



Nine examples of this very common species were found 

 by Mr. A. B. Jackson in a small stream near Port Erin. 

 They measured from 6 to 14 mm. in length and were of 

 a particularly deep black, showing none of the variations 

 so common in this species, which is frequently coloured 

 brown or grey, and presents all gradations from these 

 colours to black. 



II. KHABDOCOELIDA. 



A. ACOELA. 



Aphanostoma diver sicolor, Oersted. 



