172 
The Irish Natiiralht. Augnst-Septcmber, 
diameter dredged off Church Island, Skerries, July, 1913, 
two in 14 f., the other in 15 f. : A^C. 
The Dalkey and Skerries specimens were all similar in 
colour, the mantle being netted with chestnut brown on a 
yellowish ground, the brown colour surrounding the 
numerous large and small tubercles which studded the 
mantle surface. The wide foot with flexible waved margins 
projected somewhat beyond the mantle and was pale buff 
in colour with faint pinkish lines and blotches. At its 
posterior end was a conspicuous wedge-shaped slightly 
depressed area, the apex pointing forwards, and in form 
resembling the reflexed tail of a crab. The tubercles of 
the mantle were highly extensile. Dome shaped while 
retracted, they were frequently protruded into fleshy cones 
up to 5 mm. in length. The mantle epidermis was stiffened 
by spicules, irregularly^ stellate and usually 5 -rayed. These 
were large and thickly aggregated round the bases of the 
tubercles, small and thinly-sown in the interspaces. The 
radula and tessellated jaws were very similar to those of 
P. phmiula, the dental formula of the largest specimen 
being 57 x 75 •0-75. 
When placed in large jars soon after capture all of the 
three specimens taken were seen to float foot upward in the 
water and to progress by gentle undulations of the foot- 
margins. The largest specimen lived in captivity for two 
days, and at intervals protruded a long and flexible proboscis 
extending fully an inch in advance of the tentacles. The 
animal crawled very slowly, adhering only by the extreme 
posterior end of the foot, its rate of travel being i inch in 
2 mimites. 
P. plumula (Montagu). 
Not infrequent under stones between tide-marJcs. Dublin 
Bay : Kinahan, '61. Portmarnock (Warren Coll., Dublin 
Mus.), Nichols, 1900. Three specimens at low water, Red 
Island, Skerries, 1906, and 3 others at Shennicks Island, 
1906-08 ; 10 specimens at low water, Sandycove, 1908-14 : 
N,C. Larjjest, 61 mm. lon^- while in motion. 
