1909. COLGAN. — Dublin Marine Biology. 169 



surrounded by a transparent mucous mass in which were 

 embedded many perfectly globular, bright orange-coloured 

 eggs of large size compared with those of Limapontia, but far 

 less numerous. In a short time the animal moved away, leaving 

 behind it the floating egg-mass which, unlike the spawn of 

 most of the Nudibranchs, showed no approach to a ribbon 

 formation. It was, in fact, amorphous. On the 3rd June 

 segmentation was seen to be well advanced in several of these 

 egg- J but, unfortunately, I did not succeed in hatching out 

 any of them, nor, indeed, any of the numerous Limapontia 

 ova deposited a few days earlier. Out of the scores of Runcina 

 I have kept in confinement from time to time, and often for 

 long periods, this is the only case of spawning I observed. 



June 4th. — A fourth visit to the Bullock shore gave five 

 specimens of Runcina on Coralliyia officinalis and seven of 

 Limapontia, the latter as before on Cladophora. 



Junk 13th.— On the Field Club excursion to Dalkey Island 

 this day, in addition to ActcEoriia corrugata and Limapontia 

 alread}' recorded ^ three well-grown individuals of the rare 

 cream-coloured Do7'is Jolmstoni were found, the two largest 

 being a little over two inches long. This Nudibranch does 

 not appear to have been recorded for the Dublin coast since 

 1845, when Thompson included it in his Additions to the 

 Fauna of Ireland' as found the previous year at Skerries by 

 Mr. Hyndman. 



July 31st. — During a second dredging trip in the Dalkej^ 

 district on this date, a scrape in 17 fathoms east of the 

 Muglins gave one specimen of the rare little crab Ebalia 

 Penna7iti with two of the far less rare, though, in Dublin 

 waters, by no means common Euronyme aspera. A haul in 

 16 fathoms to the south of the Batter}- on the island brought 

 up one good specimen of the rare Trophon truncains and a 

 single valve of the much rarer Pectcn siniilis, first added to the 

 Dublin marine fauna in one of the Committee's dredgings near 

 the same ground in 1907. But the best result of the day's 

 work was had in the Sound itself, where a haul in 8 fathoms 

 produced one well-grown specimen of Idalia aspefsa, a nudi- 

 branch new to the Dublin marine fauna, though recorded in 

 1855, from off Bra}- Head, a few miles to the southward 

 (Aid. and Han., Monooraph^ ^PP^- 



^ Irish Naturalist, 1908, p. 164. 

 "^ A7i7i.and Mag. Nat. Hist., xv., p. 308. 



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