APODA. i'2'.i 



transparent circle. On full considerations of the descriptions and figures 

 oi P.Jlexilis, Dalyell, and P.sithauriculata, Johnston, I cannot — although 

 it is opposing my ignorance to Dr. Johnston's knowledge of the subject — 

 believe the species to be distinct. My sjiecimens agree about equally well 

 with both species. Further, it may be remarked that my specimens have 

 presented the form of Polycdis palUdus, Quatrefages (Ann. Sci. Nat., t. iv. 

 pi. 3, f. 8, 1845), to which they seem nearly allied ; the eyes are just as 

 represented in the highly magnified fig. 9 of that species. It was obtained 

 by M. Quatrefages on many parts of the coast of Sicily. The P.Jlexilis 

 was procured in the Firth of Fortli, and P. suhauriculata in Berwick 

 Bay. 



P. stdf/nalis, Mi'iU. 

 North of Ireland, Mr. Templeton. 



P. lactea, Miill. 



This species is marked with doubt from the circumstance of its differ- 

 ing in the folIoMing characters from P. lactea. The chief central vessel 

 represented in the figure as of about equal breadth throughout, expands 

 in this into an ovate form about the centre of the body — and the ramifica- 

 tions from it, represented as purple in P. lactea, are in this of a rich fawn- 

 colour. My specimens are 9 lines in length, when the breadth is 2 lines ; 

 eyes pyi'iform, generally two in number, placed as in P. lactea (a speci- 

 men had two at one side, and one eye at the other) ; colour milk-white, 

 but the main vessel and its ramifications, sjn-eading throughout all the 

 body except the mere margin, imparts a handsome delicate fawn-colour 

 to the animal. All of the many specimens taken were of the same colour ; 

 the size already noted marks them as considerably larger than Muller's. 

 When in motion they were generally more elongate (of about equal 

 breadth throughout) than P. lactea is represented to be, but occasionally 

 appeared of the same form as the figure in the Zoologia Danica. 



During an excursion round the shores of Lough Neagh at the begin- 

 ning of August, 1846, when I was accompanied by A. H. Haliday, Esq., 

 this species was found to be very common, attached to stones at the 

 margin of the lake, and to subaquatic plants. It was gregarious, several 

 individuals being generally adherent to the under side of a stone a few 

 inches in diameter. 



P. nir/ra, Mull. 



This species was found abundantly in the same localities, and under 

 similar circumstances with the last. With the unimportant exception of 

 being more of a brown colour and of rather less size, they perfectly 

 agreed with the figure in the Zoologia Danica, and also with the descrip- 

 tion, so far as given. They were when fully extended 3 lines in length ; 

 under a high magnifying power a row of black dots appeared closely dis- 

 posed round the margin of the anterior part of the body. Sir John G. 

 Dalyell figures similar dots in his P. niyra (Observations on Planaria^. 

 fig. 5), but in my specimens there are three for one represented in it — in 

 the description however they are mentioned as numerous. 



Atif/ust 22, 184(). — Three Platiarice, agreeing with Sir J. G. Dalyell's 

 P. nitjra, and brought from the pond in the Zoological (harden, Phcenix 

 Park, Dublin, witii Ilijdra, ike, in j\Iay last, are now living before me. 

 These differ from the P. nvjra of the Zool. Dan. in being of a jet-black, 

 of a much softer consistence, more shapeless, and being able to diminish 

 themselves to a much less size. 



