including species new to that of Britain. 389 



rious, several individuals being generally adherent to the under side 

 of a stone a few inches in diameter. 



Planaria nigra, Miiller, Z. D. vol. iii. p. 48. pi. 109. figs. 3, 4. 



This species was found abundantly in the same localities, and 

 under similar circumstances with the last. With the unimportant ex- 

 ception 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 description, 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 disposed round the margin of the anterior part of the 

 body. Sir John G. Dalyell figures similar dots in his P. nigra (" Ob- 

 servations on Planariae," fig. 5), but in my specimens there are three 

 for one represented in it — in the description however they are men- 

 tioned as numerous. 



August 22, 1846. — Three Planaria agreeing with Sir J. G. Da- 

 lyell's P. nigra, and brought from the pond in the Zoological Garden, 

 Phoenix Park, Dublin, with Hydra, &c. in May last, are now living 

 before me. These differ from the P. nigra 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. 



When at rest they sometimes appear as a round black spot, not 

 more than half the size of the other when contracted to the utmost, 

 though when stretched out they reach its full dimensions : — they are 

 much more protean in the forms they assume. The softness alluded 

 to is well shown in Daly ell's figure 15 — the L. Neagh specimens are 

 alwa)^s of a firm consistence. When changing the water on these 

 Planaria, the individuals (I shall not call them distinct species) from 

 each locality exhibited a marked difference, though all appeared in 

 equally good health, the latter always retaining their hold against 

 the sides of the phial, while the others, though the liquid was poured 

 out in the gentlest manner, became detached. Specimens which I 

 have obtained on subaquatic plants in ditches at the outskirts of 

 Belfast were similar to those from Lough Neagh. 



Planaria torva, Mull. Z. D. vol. iii. p. 48. pi. 109. figs. 5, 6. 



Several individuals just as described and figured in the work re- 

 ferred to were obtained under stones at Church Island, Lough Beg 

 (adjoining L. Neagh), on the occasion alluded to under P. lactea. 

 Templeton notices " P.fusca, Pallas," as Irish (Mag. Nat. Hist, 

 vol. ix. p. 239) without giving any particulars respecting it. This 

 species and P. torva are said by Duges to be identical (Lamarck, 

 2nd edit. vol. iii. p. 607). 



Nephelis octoculata, Moquin-Tandon, Monog. Hirud. p. 302.pl. 3. 



figs. 1-11. 2nd edit. 



Four individuals of this species found among subaquatic plants at 

 Lough Neagh on the occasion already alluded to were brought home 

 for examination. They were not more than half the size of those 

 figured by M.-Tandon, nor of so dark a hue generally — anteriorly 



