Niphargus Kociu'anus and N. subterranens. 277 



But it is remarkable that in considerable oceanic depths a 

 strange uniformity of orange coloration obtains amotv^ 

 Crustacea, Hydroids, and other marine organisms, a remark- 

 able instance of which the writer once had the opportunity of 

 observing. Chilton, quoting from Prof. S. f. Smith on this 

 phenomenon, goes on to say that he has been unable to find 

 any parallel instances of this that are in any way conclusive 

 with regard to the animals found in the deep waters o£ lakes, 

 such as those of Switzerland. In the present case, therefore, 

 the orange colour of the Lough Mask Niphargus is notable. 

 Sp^■cimens from the Dublin well are diaphanous. 



The following are the circumstances of the capture : — Tn the 

 last days of June 1903 I made an expedition to Lough Mask, 

 in the county of Mayo, with the object of pursuing investi- 

 gations as to its Entomostracan fauna and also in the hope of 

 finding Mysis relicta. I brought with me a kind of dredge 

 designed especially for use in freshwater lakes, by the aid of 

 which I had captured that crustacean in abundance in Lough 

 Neagli and Lough Erne. By the kindness of Col. Knox, of 

 Creagh, I was provided with a suitable boat and man, and 

 spent the greater portion of a day dredging tlie deeper parts of 

 that picturesque lake in depths varying from about 100 to 

 150 teet. No Mysis were taken. By adjusting its mouth I 

 was able either to pass the net at a height of about 1 inch above 

 the level of the floor of soft mud, or to skim it so closely at 

 other times in the hope of taking Ostracoda as to pick up a 

 little of the upper layer of loose debris, much of whicli I 

 believe consisted of fish-excrement. All this was reserved 

 for future examination, and a sample of the mud itself taken 

 up by reversing the dredge. On examining this material I 

 noticed a few minute Amphipoda of an orange colour which 

 from time to time appeared on the surface of the muddy 

 water and then burrowed out of sight. They swam sideways, 

 like Gam?narus, but when undisturbed crawled in an upriglit 

 position. Of these 1 secured a small series, which were duly 

 despatched by post to the Kev. Canon Norman, whose kind 

 assistance on similar occasions has been frequently afforded 

 me ; and subsequently he wrote that he was much interested 

 in my find, which was a blind Niphargus, and that it would 

 be of importance to secure a long series if possible, because 

 some of the specimens were mutilated by the loss of the 

 terminal uropoda, and it was desirable to ascertain the sexual 

 characters. About six weeks later, therefore, I made a second 

 journey to the west, and again experienced the kind hospi- 

 talities of Creagh. The result was highly satisfactory, for in 

 two days, the first of which was so stormy that I only with 

 Ann. cfc Mag. N. Hist. Ser. 7. Vol. x'lv. 19 



