ISOPODA. 
401 
Arcturus longicornis, West. 
Leachia — Sower, (sp.). 
On examination of a specimen dredged by Mr. Hyndmanin July, 1851, 
off the Copeland Islands, in from 30 to 50 fathoms, I find it to be this 
species as distinguished from Leachia intermedia, and L. gracilis , Goodsir. 
Body of the specimen 1 1 lines in length. Antenna (inferior), if perfect, 
would be of equal length ; wanting the last segment, they are 10i lines. 
Genus Ldotea. 
I. pelagica, Leach. 
Dredged off Ballyhome Bay. Strangford Lough ; Dundrum ; Bally- 
waiter, W. T. 
Found among Derry oysters, W. T. 
J. tricuspidata, Edw. 
Down and Antrim, coasts and bays. 
Donaghadee, 8 — 10 fathoms, Dr. Drummond. 
Dublin Bay, Professor Allman. 
Connaught ; Lahinch, Co. Clare, W. T. — both littoral and dredged. 
I have found it in the stomach of gulls. 
I. emarginata, Edw. 
Templeton’s notes, “ on rocks.” 
Dundrum, 1836, W. T. 
August 26th , 1836. I should suppose that plants are as food especial fa- 
vourites with this ldotea , as when looking over heaps of sea-weed, contain- 
ing many different species, thrown among the rocks at Newcastle (in the 
Co. of Down), I found the Mesogloia vermicularis variously attacked by 
numbers of them, and every piece of it I saw had been more or less con- 
sumed by them. The other plants had not been touched, nor were any 
ldotea upon them. It should be stated that the Mesogloia did not consti- 
tute more than perhaps a 28th part of the mass of sea-weeds. 
I. linearis , Edw. 
Newcastle and Dundrum, W. T. 
South of Ireland, J. Y. Thompson. 
Youghal, Dr. Ball. A specimen thence 2\ in. long, including antennae. 
I. acuminata, Leach, 
Among Crustacea kindly sent from Dublin for my inspection by Dr. 
Ball, were two individuals of an ldotea 10 lines in length, very dis- 
tinct in form from our three common species, the I. pelagica, I. entomon , 
and I. oestrum of Leach. They were purchased of Mr. M‘Calla, but on 
what part of the coast taken was not stated. I mark the species with 
doubt on account of Leach’s only specimen in the British Museum, with 
which they were compared, being in a bad state of preservation. The I. 
acuminata was first noticed in the British Museum Catalogue of Crus- 
tacea, p. 95 (published in 1847), as among Dr. Leach’s inedited species. 
He obtained it on the coast of Devon, and called it in his MS., Leptosoma 
lancifer. 
