July, 1901. 133 



NOTES ON IRISH PI.ANARIAN WORMS. 



BY R. F. SCHARFF, PH.D., M.R.I.A. 

 (Collected for the R. I. A. Fauna and Flora Committee.) 



IyAST year I published a short account of the species of 

 I^and Planarians inhabiting Ireland 1 . I pointed out that of 

 the three different kinds which had been discovered in this 

 country, one, Placoccphalus Kewensis, had probably been intro- 

 duced with plants from the Oriental Region ; and that of the 

 remaining two, only one, Rhynchodemus terrestris, was un- 

 doubtedly a native, while the other, Rh. Scharffi, had so 

 far been found in two localities only, and under such circum- 

 stances that its artificial introduction seemed likely. 



L,and Planarians being mostly confined to the Tropics, the 

 discovery of an additional European species of this peculiar 

 group of worms is always an interesting event. I am glad, 

 therefore, to announce that, last April, while on the way to 

 visit a cave near Ballymote, Co. Sligo, with Mr. Praeger, we 

 met with several specimens of Rh. Scharffi under a tree trunk 

 which lay close to the road. Artificial introduction of the 

 worm in this locality is, I think, out of the question, and we 

 can now safely add this species to the native Irish fauna. 



Two of the specimens found were of a light salmon and 

 another of a primrose colour, about ij-inch.long (30 mm.). 

 Under a lens the two eyes were clearly visible, and having 

 taken several specimens of Rh. terrestris at the same time, I 

 was able to make a few additional notes as to the principal 

 external distinguishing characters between the two species. 



Apart from the colour, which differs in the two species, 

 Rh. terrestris being either light or dark grey, the body in the 

 latter is much more regularly rounded, so that the sole on 

 which the worm creeps is considerably narrower than in Rh. 

 Scharffi ; the worm is also quicker in its movements. The 

 underside in Rh. Scharffi is yellowish while in Rh. terrestris it 

 is white. The anterior portion of the body can be drawn out 

 to an exceedingly fine point in Rh. Scharffi, so that the head 

 region is always much narrower than in Rh. terrestris. 



Science and Art Museum, Dublin. 



1 Irish Naturalist, vol. ix., 1900, pp. it 5-2 18. 



A 



