580 f. f. laidlaw. 



Note on Leptoplana pardalis Laidlaw. 



Since my account' of Mr Gardiner's marine planarians was published, I find that I had 

 inadvertently overlooked the description of Leptoplana subviridis v. Plehn, given by von Plehn 

 in Semon's Zool. Forschungreisen, 5, III. p. 330, PI. XXIII. figs. 11, 12. Since three of the 

 four species described and figured in this paper are also described with the same figures 

 in von Plehn's previous paper in the Jena Zeitschrift, I had carelessly put the former on 

 one side, supposing that all the species described in it were also described in the latter. 



I find now that the species which I overlooked is identical with my Leptoplana, pardalis, 

 which therefore becomes merely a synonym of L. subviridis. I find, however, that there are 

 certain discrepancies between our accounts especially as concerns the male apparatus. I have 

 re-examined my sections in consequence and give the following comments. 



As regards the vesicula seminalis, von Plehn states that the vasa deferentia have muscular 

 walls and open together into a vesicula seminalis. In my account I stated that the lower 

 ends of the vasa deferentia were dilated to form a pair of vesiculae which opened into 

 a ductus ejaculatorius. In favour of this latter view I find that in my specimens at any 

 rate, the ends of the vasa deferentia are distinctly dilated, and that the vessel called the 

 vesicula by von Plehn is narrow and of the same diameter throughout, until it decreases 

 on approaching the penis. In support of von Plehn's view is the fact that her interpretation 

 is more in accord with the condition usually found in Leptoplanas. I am inclined to believe 

 that both views may be right in this case, i.e. that either the lower ends of the vasa 

 deferentia, or the part which I have called the ductus ejaculatorius may function as 

 a vesicula seminalis. 



Von Plehn's specimen does not appear to have shown the very distinct narrowing of the 

 two parts of the accessory vesicle and their subsequent dilatation to form a receptaculum 

 seminis on either side, so that each receptaculum is placed as it were on a distinct stalk. 



The synonymy of this species then stands as follows : 



Leptoplana subviridis v. Plehn. 



L. subviridis von Plehn. Semon's Zool. Forschumjreisen, 5, III. p. 330. Tf XXIII. figs. 14, 15. 



L. pardalis Laidlaw. Faun, and Geogr. of the Maldives and Laccadives, i. 3, p. 287, 

 PI. XIV. fig. 9, PI. XV. fig. 14. Ibid., Proc. Lit. and Phil. Soc. Manchester, xlvii. (1903), no. 5. 



I take the opportunity of thanking Mr Stanley Gardiner for permission to call attention 

 to my oversight, which I greatly regret to have committed. 



' "The Marine Turbellaria, etc." Fuuiia ««(( Geogriiphij, Maldioes and Laccadives, vol. i. pp. 281—310 (1902). 



