172 The hish Naluralist. August, 



the yellow sponge. It agreed closely with Alder and Han- 

 cock's figure, save thai its dorsal tentacles were much more 

 wrinkled than is there shown, and the tips of its papillae, at 

 the time of capture, were almost colourless instead of orange. 

 Yet the living animal, on the 21st June, showed distinct 

 orange yellow blotches on many of the papillae. There 

 appears to be only one previous record for E. Dnifn/noiidi in 

 county Dublin waters, the record by Professor Haddon of its 

 discovery in Kingstown Harbour, about the year iSSi.^ 



July 27th. — A third dredging trip in Malahide River, 

 though it added no mollusca new^ to the Du1)lin marine fauna, 

 gave one specimen each of three interesting opisthobranchs, 

 Elysia viridis, A/Lcitla crisiaia, and Eolis aerulea. The speci- 

 men of is. cwricha was the second found in. Dublin waters, the 

 first having been taken in one of the Committee's dredgings, 

 on the same ground, in 1907. Many large .specimens of 

 Alcyonidmni oelatinosiiDi came up in the dredge here, and on 

 one of these five living individuals of the rather rare Lacuna 

 eras si or were found. 



NovEMBKR nth. — The last Malahide dredging of the year 

 w^as made this day in cold and squally weather. The tide 

 suiting, several scrapes were made on the Zostera beds in the 

 creek. Three Runcinas and one Chiton IcEvis were taken on 

 old oyster shells, and on the Zostera one living Plciirotoma 

 ) iifa and numerous fine living specimens of the common 

 Lacuna divaricata. The Lacunas offered an interesting 

 example of what appears to be protective colouring. Observ- 

 ing that the individuals of this species, though large and 

 numerous, were yet hard to detect on the living Zostera to 

 which they clung, I examined the shell and animal closely 

 and found that both w^ere distinctly streaked or blotched with 

 rather bright green. This colour appeared on the operculum 

 of almost all the individuals and in various positions on the 

 shell, while the head of the animals and the tentacles, when 

 protruded in crawling, were found to be distinctly tinged with 

 the same colour. The ground colour of the shell being taw^ny, 

 with brown bands, the individuals, whether at rest or in motion, 

 harmonized closely with the green and often mud-stained 



' Proc. A'. I. A, ad., iS86, p. 529. 



