September, I9I3- The Irish NatiLvalisi 165 
SOME ADDITIONS TO THE NUDIBRANCH FAUNA 
OF COUNTY DUBLIN. 
BY NATHANIEL COLGAN, M.R.I. A. 
Further exploration of the marine molluscan fauna of 
the inshore waters of County Dubhn has shown that in one 
group at least our knowledge of that fauna is by no means 
complete. The dredgings and shore collectings of the past 
two years, carried on at Dalkey, at Malahide, and at Skerries, 
have added no less than eight species of nudibranchs to the 
fauna of the shores and shallow waters of the county, and 
brought up the Dublin total for this most interesting group 
to well over 40 species. The eight new species are the 
following : — 
Aeolidiella Alderi. Cory phe 11a gracilis. 
Cratena amoena. C. Landsburgii. 
C. viridis. Tritonia plebeia. 
Embletonia pallida. Triopa claviger. 
Three of these additions to the Dublin fauna appear to 
be additions at the same time to the fauna of Nichols's 
Irish Marine Province II., comprising the east coast from 
Carnsore Point north to St. John's Point in Down^ ; another 
of the additions, Emhletonia pallida, is apparently new to 
Ireland ; and the remaining four species, though additions 
to the Dublin shallow-water area lying within the 3 miles 
limit from the shore line, have already been recorded for 
the deeper waters outside of that limit yet off the Dublin 
coast. 
Brief notes, descriptive and critical, on these additional 
species are added here, references to Mr. G. P. Farran's 
'* Nudibranchiate Mollusca of the Trawling Grounds of the 
East and South coasts of Ireland- being distinguished by 
the contraction, Farran '09. 
Aeolidiella Alderi (Cocks). — A single specimen, 30 mm. 
in length, was found under a stone at low water, Dalkey 
Island, on the i6th May of this year. At first I set this 
aside as a colour variety of the rather common Eolis 
^ List of the Marine Mollusca of Ireland. Proc. R. I. Acad., 1900. 
' Fisheries, Ireland ; Scient. Investig., 1907, vi. [1909]. 
