200 ~—-Dr. C. Collingwood on the Nudibranchiate Mollusca 
in the fact that these specimens were placed in a shallow glass 
dish, and in a situation constantly exposed to draughts of fresh 
air, which kept the water well aérated. 
The five species of Nudibranchiata which have been met with 
in the Dee only, and not in the Mersey, are the following :— 
1. Doris depressa. This scarce little Doris, remarkable for 
the great relative size of the spicula, was once taken by Mr. 
Byerley at Hilbre Island. 
2. Doris subquadrata. Only two specimens of this rare Doris 
appear to have been yet seen. The first was discovered by Mr. 
Alder, m deepish water at Torbay, in 1845 ; and the second was 
found by Mr. Byerley at Caldy Blacks, in the Dee. This spe- 
cimen was forwarded to Mr. Alder, who confirmed the fact of 
its being D. subquadrata. I believe it has never been taken 
since. It was in company with Doris pilosa, to which species it 
is closely allied, but yet differs from it in several points, and 
particularly in the degree of development of the pallium, which 
in D. subquadrata is so scant as to leave the head and posterior 
part of the foot uncovered, when the animal is extended. 
3. The third peculiar Dee species is the Eolis olivacea. 
The last excursion of the Liverpool Naturalists’ Field Club 
was to Hilbre Island, on which occasion, notwithstanding that 
the day was hopelessly wet, it was not sufficiently so to damp 
the ardour of ninety-five members and friends of this flourishing 
Club. A few only landed ; but among the captures I was glad 
to number Clavellina lepadiformis, new to our local list of Tuni- 
cata, while, among some Zoophytes brought from the island by 
Dr. Edwards, there appeared a specimen of the above Kolis not 
hitherto known in this locality. It was a small specimen, very 
brilliantly coloured, and altogether a very elegant addition to 
our fauna. 
4 & 5. But the most interesting genus of all is perhaps that to 
which the remaining two species belong. I refer to Antiopa, the 
history of which is not a little remarkable. In 1844, M. Verany 
of Genoa described a species of Nudibranch inhabiting the 
shores of Southern Europe, under the name of Janus Spinole. 
The name Janus, however, having been already occupied by a_ 
genus of Hymenopterous insects, Messrs. Alder and Hancock 
proposed to call it Antiopa, in order to avoid confusion of ge- 
neric terms. The animal in question appeared to approach very 
near in its characters to Proctonotus mucroniferus; but a re- 
markable crest between the dorsal tentacles, added to the lamel- 
lated form of the tentacles, and the terminal branching of the 
biliary cells of the papillae, appeared to warrant its separation 
from the genus Proctonotus ; and for seven years it constituted 
the sole species of the genus, under the name of Antiopa splen- 
