ON CRUSTACEA OF DUBLIN DISTRICT. 263 
Dalkey Sound, a narrow channel, separating Dalkey Island from the main 
land and from 3 to 10 fathoms deep, bounds the Dublin station. In the 
Sound, the following species occur:—Portunus depurator, puber, holsatus and 
pusillus, Inachus Dorynchus and Dorsettensis, Hyas coarctatus, Eurynome 
aspera, Pirimela denticulata, Pinnotheres pisum, Ebalia Pennantii and 
Cranchit, Bernhardus Streblonyx, Thompsonii, Cuanensis, Ulidianus and 
Hyndmanni, Galathea Andrewsii, strigosa and squamifera, Palinurus vul- 
garis, Hippolyte varians, Thompsonii and pusiola, Pandalus annulicornis, 
and many of the commoner species. 
Killiney Bay, which succeeds this, and is bounded by Bray, is partly sand 
and part shingle and rocks; it calls for no detailed description. At Bray the 
Bray river enters and forms a mud bank in about 10 fathoms to the south 
of Bray Head; here, in the lobster pots, Palemon serratus has been said to 
have been taken. Distant about 7 miles from Bray Head is a bed called 
the Scallop bed, part of the Kish bank, the water varying from 6 to over 25 
fathoms. Here many rare and one previously undescribed species has 
occurred, suchas Crangon sculptus, Crangon Allmanni, Galathea Andrewsit, 
all the Bernhardi, except Prideauaii, the two Ebalias already mentioned, 
Acanthonotus testudo, Ampelisca typicus, Nephrops Norvegicus. 
The North Bull, owing to the influx of the three rivers already named, is 
chiefly mud passing into rock at Howth: this district has never been care- 
fully explored, but the following species are often thrown upon the white 
sand, a bank similar to that already noted as the South Bull: Corystes Cas- 
sivelaunus, Portumnus variegatus, Pilumnus hirtellus. 
Balscaddan Bay, Howth, is rocky; here Amphitoe littorina is common, 
Hippolyte varians, Hippolyte Cranchii, Mysis vulgaris and chameleon, 
Porcellana platycheles. 
Portmarnock Bay, which next sueceeds, is chiefly sandy, slob banks occur- 
ring in parts. At Malahide a great muddy estuary, due to the influx of the 
Swords river, is found. This mud slob is separated from that at Rush and 
Lusk by the Burrow of Portrane, which is sandy like the two Bulls; to the 
north of this the coast becomes rocky till we get to Skerries, where three 
islands cause the formation of a bank, from which in 10 fathoms the late 
Robert Ball, LL.D., procured Crangon trispinosus, and Diastylis Rathkii. 
From Skerries to the mouth of the Boyne the beaches are all sandy, and 
call for no special remark. b 
Two outlying stations, viz. Ireland’s Isle, or Eye, near Howth and Lambay, 
which lie abreast of Portrane, have afforded many rarities; but never 
having personally examined them, I must defer particular notice of them till 
some future period. ; 
The fluviatile districts afford us Astaeus fluviatilis, Gammarus fluviatilis, 
besides Entomostraca in abundance. At the mouths of rivers many of the 
marine species ascend even into the fresh water; these are marked in the 
accompanying Tables as subfluviatile; they are Crangon vulgaris, Mysis 
chameleon? and vulgaris, Gammarus fluviatilis, Spheroma serratum, 
Orchestia levis, Orchestia littorea, Corophium longicorne, Carcinus Menas. 
The terrestrial species are at present recorded in greater numbers than in 
any other district, probably having been more sought after, all the genera, 
save Platyarthrus, being represented here. The chief species wanting in the 
Dublin lists are those which frequent deep water, and which will probably 
be yet found when the deeper parts of the Bay are better searched. Mud 
burrowers are also absent, which will most certainly yet be found. It is 
intended to embody all remarks bearing on the peculiarities of the distribu- 
tion of species in the last part of this report; at present I shall content myself 
