I0T4 CoLGAN. — Opisthobrancii Fauna of Co. Dublin. 169 
P. pruinosa (Clark). 
Rare. One shell, 3 mm. in IcMigth, found in drift on the 
North Bnll, 1906 : Colgan, '06. 
P. catena (Montagu). 
Rare, living in dredgings and between tide marks, shells 
in drift and in dredgings. Dalkey Sound, very rare : Wal- 
pole, '53. One shell in each of four drift gatherings at 
Lambay, Portrane, Portmarnock and N. Bull, 1906 ; off 
Dalkey, 3 shells, 10-16 f., and one living specimen in 17 f., 
1906-08 : N.C. One living, in a half -tide pool, Shennicks 
Is. : Colgan, '09. One, living, in Dublin Bay : Massy, '12. 
Largest, 3 mm. long. 
Runcina coronata (Quatrefages). 
R. Hancocki. 
Locally abundant, living between tide-marks and not 
infrequent in shallow water dredgings. Several specimens 
on S.W. shore of Lambay Island (H. J. B. Wollaston), 
Colgan, '07. Eight specimens dredged in 2 f. in Malahide 
River, 1907-08 : 43 specimens taken between tide marks, 
Bullock and Dalkey Islands, 1907-12 : N.C. Largest, 6-5 
mm. in motion. 
This species was found to be frequent between tide- 
marks along the Dublin coast for at least 8 months in the 
year from November to June inclusive. Several individuals 
taken at Bullock were found to have slender, pear-shaped 
bodies of whitish colour protruding from the head, the back 
and the foot. These were probably the egg -sacs of parasitic 
copepods. Like many of the true Nudibranchs Runcina 
is able to suspend itself from the water surface by a shme 
thread and to regain the surface by climbing the thread. 
In May, 1908, one was observed to mount in this way for 
half an inch in the space of two minutes : Colgan, '09A. 
Aplysia punctata (Cuvier). 
Occasional in dredgings ; sometimes abundant between 
tide-marks. Dublin (R. Ball), TJiovipson, '40. Dredged 10 
A 3 
