14 Proceedings of the Royal Physical Society. 
and, for the most part, on the underside of stones and boulders, none 
being found so deep as the line of low spring-tides, and none being obtained 
in the dredge. From this they would appear to be bilamellata rather than 
pilosa. In size the winter-spring specimens measured on the average 1,15 in. 
by 7 in. | 
L. bilamellata is described as being “ elliptical, nearly equally rounded at 
both ends,” its cloak “covered with stout, not much crowded, clavate, strongly 
spiculose tubercles,” and with the underside “slightly granulated.” D. pilosa, 
on the other hand, is “ovate, very convex, and semi-transparent,” its cloak 
“covered with soft, slender, conical, pointed papille,’ with the underside 
“veined in white and usually spotted.” 
Our forms combine these characters, for most of them are rounded at 
both ends, convex (some of them very convex) and semi-transparent, whilst 
the cloak is covered dorsally with both “stout, clavate, strongly spiculose 
tubercles,” and “soft, slender, conical, pointed papille,” and its underside is 
both “granulated” and “spotted.” The branchial plumes resemble those of 
bilamellata in both structure and number, and the masticatory apparatus 
contains the erect, ear-shaped membranous fold of that species. 
Alder and Hancock found bilamellata breeding in February, March, April, 
May and June, and August and September, chiefly in February and August ; 
pilosa they found in April, May, June and as late as September, chiefly in 
May and June. Hence they suggest the probability of the former having two 
breeding periods, the one early in spring, the other late in summer. They do 
not say whether pilosa was found breeding between June and September, so 
that it is not quite clear whether this species is credited with two breeding 
periods or with but a single extended period. 
As stated in the preceding note our forms appear to have two distinct 
breeding periods, with the maxima during March and September—October, 
in this respect resembling bilamellata rather than pilosa. 
Regarding the spawn Alder and Hancock say of bilamellata :—“ The spawn 
forms a compressed coil of one, or occasionally two volutions; spreading at. 
the top, and often a little curved outwards, so as to give it a vase-like outline. 
That of a large individual measured } in. in height, and } in. in diameter at 
the top ; usually, however, it is not above half that size.” Of pilosa they say :— 
“The spawn ... 1s of a pretty, cup-like form, with the margin turned outwards, 
and in some cases a little flounced.” The spawn of our specimens resembles 
that of pidosa in arrangement and in size, for it is distinctly “ flounced,” 
and is of even larger dimensions than the spiral figured by Alder and 
Hancock, whilst the spirals of even the small summer—autumn forms much 
exceed in size those described as being typical of bilamellata. 
