t94 
The Irish NainralisL August -September, 
1912-13, a total of 17 specimens, all on Antennularia, A^.T. 
Several Specimens on Halecium inside of Burford Bank, 
1904, and one specimen in 14 f. a quarter of a mile off 
Howth, 1907 ; G. P. Fanan. Largest 30 mm. long. 
In three specimens examined the number of teeth in the 
radula was fonnd to vary from 75 to no, each tooth bearing 
on either side of the median cusp four blunt denticles. 
Dendronotus frondosus (Ascanius). 
D. arborcsccns. 
Frequent in dredgings in from 2 to 18 f. Several speci- 
mens taken by Mr. Alder and Dr. Farran at Malahide ; 
Thompson, '44. One specimen in 14 f. off Howth Head 
and another in 6 f. in Lambay Sound ; Colgan, '08. Taken 
in 15 hauls at Malahide, Skerries, and Dalkey in from 
2 to 18 f., 1906-13, a total of 21 specimens, the largest 
27 mm. long. On the 25th May, 1908, a very fine speci- 
men of this species fully 89 mm. (3?^ inches) long was 
brought to me by a Bullock fisherman who had found it 
that day in one of his lobster pots sunk off the harbour 
at a depth of 5 fathoms. I can find no larger specimen 
on record. 
The radula was examined in three specimens, a, b, and c, 
respectively, 10 mm., 25 mm., and 89 mm., in length, 
with the following results : (a) 38 rows of teeth \^ith 8 to 
10 uncini on either side ; (b) 40 rows with the uncini equal 
in number to those of (a) ; and (c) 30 rows with 10 to 
11 uncini. Here a departure from the general rule of 
increase in the number of teeth with increase of age and 
size of the animal was exhibited, the very large Bullock 
specimen having 8 rows of teeth less than were found in 
the small, 10 mm. specimen. The large specimen; a giant 
for its species, had no doubt reached the age, seldom, 
perhaps, attained by a nudibranch, when the growth of 
new teeth has either ceased or become too feeble to balance 
the loss by wear of the old teeth. In this old specimen 
too, a remarkable change in the form of the uncini was 
