10 The Irish Xaturalist. January, 



to the Irish Naturalist, August, 1917) growing in L. Ball3^1ar 

 which may serve to ehicidate the question of a possible 

 species or variety intermediate between '/. glomcrata, Leonh., 

 and T. nidifica, Leonh. 



I was also able to add another species to the list of 

 Characeae growing in L. Kindrum, viz., A^. opaca in good 

 fruiting condition, unless indeed the plant proves to be 

 A^. flexilis. In either case it adds another to the yield of 

 the lake. It seems impossible to discriminate between 

 N . flexilis and N. opaca otherwise than by the monoecious 

 character of the former and the dioecious character of the 

 latter. In plants of advanced growth where the antheridia 

 have dispersed this one distinctive and determining 

 characteristic disappears. This is the case with the speci- 

 mens both from L. Mallaghderg and from L. Kindrum. 

 The doubt can only be settled by collecting plants at an 

 earlier period of the year. 



All Hallows Lane, Londmi, E.C. 



NOTES. 



ZOOLOGY. 

 The Purple Sea-Urchin at Inishkeel, Co. Donegal. 



The island of Inishkeel lies on the south side of Gweebarra Bay opposite 

 the villages of Naran and Portnoo. It can be reached on foot at spring 

 tides by walking across the neck of sand which connects it with the 

 mainland. On the nortliern side are extensive rock pools, and it was 

 in these that Mrs. Johnson first noticed the Purple Sea-Urchin {Slrovgy- 

 locenlrotus lividus Lanik). She brought me to the spot and 1 found the 

 urchins present in considerable numbers, just as I had seen them at 

 Bundoran and Gortmore. I could not, however, find that they had 

 bored holes in the rock such as 1 had seen at Bundoran, and I onl}- 

 conjecture that they had not been there long enough to make these 

 borings. 1 sent a specimen to the National Museum, and Mr. A. R. 

 Nichols, M.A., was kind enough to confirm by identification and to 



