248 Mr. Thompson's Additions to the Fauna of Ireland. 



single individual of this extremely beautiful species (of which 

 Montagu's two original specimens only have, I believe, hitherto 

 been recorded) was taken by Mr. Hyndman and myself when 

 dredging in Strangford lough on the 1st of October — in size it 

 exceeded Montagu's, being 2 inches in length and one in breadth. 

 It was of a whitish cream colour with black lines, occasionally 

 broken or non-continuous, disposed longitudinally over the up- 

 per surface of the body, not unlike those which on a whiter 

 ground render so attractive the plumage of the male silver 

 pheasant (Phasianus nycthemerus) : these lines are from the de- 

 licacy of the animal all visible when the under side — which in 

 itself is plain white — is next the spectator ; it was surrounded 

 by a border of pure opake white, which from the transparency 

 of the entire body within imparted a beautiful finish to its ap- 

 pearance : the two auricular appendages which emanate from the 

 anterior margin exhibit a black hue along their basal half pos- 

 teriorly ; eyes could not be distinguished. 



This Planaria was in form quite a proteus, and gliding with 

 an easy motion folded itself gracefully over every object that 

 came in its way. Having placed it in a phial of sea water, one 

 half of the body rested on the bottom and the other against the 

 side, and being thus at the same time horizontal and perpen- 

 dicular, and presenting throughout its entire length one mass 

 of folds, of which no two were alike in size, it looked as sin- 

 gular as beautiful. Montagu's figure, though correct, gives no 

 idea of the grace of the original ; as usual, his description is 

 admirable : he remarks, that a drawing was fortunately made 

 from his specimens, two in number, upon the day on which 

 they were procured, as next morning they had disappeared, 

 having been dissolved in the sea-water. 



ACALEPHA. 



Medusa papillata, Abilg. in Zool. Dan. vol. iv. p. 24. t. cxl. Of this 

 very minute species, 11 line in diameter, a specimen occurred 

 to me in Strangford lough in October. 



Medusa (Geri/onia) hcemisphcerica, Mull. Z, D. vol. i. p. 6. t. 7. On 

 October 5, 1838, I obtained one of these Medusee in Belfast bay, 

 and a day or two afterwards many specimens were brought me 

 by Mr. Hyndman from the same locality : in size they rather 

 exceeded Muller's, measuring 5 lines in diameter in their most 

 depressed state. This and the preceding species were deter- 

 mined from accurate drawings taken of the living animals. Mr. 



