April, 1908. The Irish Naturalist, 69 



SOME COUNTY DUBININ HOLOTHURIANS. 



BY NATHANIEL COI.GAN, M.R.I.A. 



Thkre can be little doubt that all of the species of the Holo- 

 thurian division of the Echinoderms are rare on the coasts of 

 Co. Diiblin. Of the fifteen species known to occur in 

 the shallow water area of Ireland, ^ onlj^ four have been 

 recorded for Co. Dublin, and, with one exception, these 

 records are at least 45 j^ears old. Evidently much remains to 

 be done in working out the Irish distribution of the 

 Holothurians, and it is hoped that the following notes, giving 

 the meagre results of the wTiter's shore-collecting and dredg- 

 ing in 1906, may act as a stimulus to further investigation. 



CucuMARiA PENTACTKS, Linue. 



A single specimen of this species occurred to me at Shen- 

 nick's Island, Skerries, under a stone at lov/ w^ater, on the 

 25th July, 1906. It was cream-white in colour, the mouth 

 ringed with browm, and the tentacles spotted with the same 

 colour on a yellowish ground. At rest, the animal was one 

 inch in length, and in motion extended to rather more than 

 \\ inch. Two out of the ten tentacles were much smaller 

 than — indeed, little more than one- third the size of— the 

 remaining eight, and these two were contiguous. 



With occasional changes of water this specimen lived wdth 

 me for eight days in a small glass tube, 2 inches long by 

 |-inch wide, and passed one night, or, at all events, some 

 hours of it, entirely out of water. This last severe test of its 

 vitality was undesigned. On going to bed the second night 

 after the capture of the animal, I left it in its open tube of 

 sea-water on the dressing-table in my bedroom. When I got 

 up next morning, eager to resume my observations on the 

 manners and customs of the interesting captive, I found the 

 tube unoccupied, and after a vain search on the floor for the 

 absconding tenant, finally discovered it far under the stand 

 of the looking-glass, where it lay high and dry, and reduced 



■• See A. R. Nichoi^S, " A List of Irish Echinoderms.'' Froc. R. I. Acad ^ 

 vol, xxiv., p. 231. 



