64 Mr. W. Thompson's Additions to the Fauna of Ireland. 
developed species, and consequently am of opinion that w'hat Muller 
considered its adult state is another species. 
Amaroucium albicans^ Edw. Ascid. Comp. p. 71. pi. 1, 3 h. 
Dredged from several fathoms in Belfast bay (1839) and on the 
Galway coast (1840), W. T. 
Mr. iVJcCalla mentioned to me last spring that he had collected 
this species on the Irish coast. 
Didemnum gelatinosum, Edw. Ascid. Comp. p. 79. pi. 7. f. 5 ? 
Adherent to Serpula tubularia dredged in Strangford lough, Oct. 
1839, &c., W. T. 
A species apparently of this genus may not uncommonly be found 
investing the stems of Halidrys siliquosa. It is of a pale gray colour, 
and may l)e said to give the plant the appearance of being besmeared 
with bird-lime. 
Botryllus violaceus, Edw. Ascid. Comp. p. 89. pi. 6. f. 4. 
On Fuci, Belfast bay, W. T. 
Botryllus smaraydus, Edw. Ascid. Comp. p. 91. pi. 6. f . 6 ? 
A species taken at Holywood, Belfast bay, by Dr. J. L. Drummond, 
in the summer of 1846, of which he made a drawing and noted the 
colour, seems to be the B. smaraydus. The notes are not in sufficient 
detail to ensure certainty. 
The last four have not, that I am aware, been made known as 
British species : — the genus Didemnum indeed seems unnoticed. Dr. 
Scouler has met with it on the Irish coast. 
Crustacea. 
Crangon fasciatusy Risso, Hist. Nat. de FEur. Merid. v. 64 ; Edw. 
Hist. Crust, iii. 342. 
Among Crustacea lately submitted to my examination by Mr. R. 
Ball are two individuals of this species, which were taken by him at 
Bray in July last. They are nearl)'- one inch in length, and exhibit 
masses of mature ova. The species is admirably characterized in 
Milne-Edwards’ description above referred to. Its short thick form 
at once arrested my attention as distinct from that of C. vulgaris : — 
the colour designated by the trivial name fasciatus does not so distin- 
guish it. One specimen exhibits a blackish band on the fourth seg- 
ment of the abdomen and the other none ; and the greater number 
of specimens of C. vulgaris from various parts of the Irish coast 
examined in reference to this character have more or less of a blackish 
band on this segment. It is slightly shown too in Sowerby’s figure 
on Leach’s Malacost. Podophth. Brit. This species has not been 
noticed as British, but has I believe been lately obtained by Professor 
Bell. 
