SPONGES. 
481 
II. ventilabra, Flem. 
Specimens of this sponge (with one of which I have been favoured) 
were obtained by Dr. Ball from the Nymph Bank, in 1818. 
II. simulans, Johnst. 
Dublin Bay, Dr. Hassall. Connemara, Mr. M‘Calla. 
H. cinerea, Grant. 
East and West of Ireland, Clew Bay, W. T. 
H. fucorum, (W. T.) See Johnst. Br. Sp., p. 112 and 113. 
In Belfast Bay I generally find this species, as it is represented in pi. 
ix. of Brit. Sponges, on Halidrys siliquosa. When exposed for a time on 
the beach, it assumes a brilliant orange colour. Killery Bay, 1840, W. 
T. Common on Algse and Zoophytes (littoral and deep-water), Down 
and Antrim. Not uncommon on marine plants and the large corallines 
on the North-East coast, W. T. 
H. panicea , Pall. 
In addition to bringing Templeton’s sp. urens and cristata under 
this, Johnston also brings his Alcyonium tomentosum and medullar e (var. 
S. tomentosa , common on Algse and Zoophytes, Down and Antrim). This 
species invests Inachus scorpio, in the North. Burren, Co. Clare, 
W. T. 
Spongia palmata, Templeton. A var. H. panicea , Johnst. Br. Sp., 
p. 94. 
This species is most common, investing to a great extent the stems of 
Laminaria digitata , on the coasts of Down, Antrim, and Dublin. 
II. cegagropila, Scouler. 
On ovum of common dog-fish, brought with Derry oysters to Belfast, 
W. T. Connemara, Mr. M‘Calla. 
H. incrustans, Esper. (sp.). 
Abundant, adherent to rocks between tide-marks on the Down coast. 
Dr. Johnston calls it an “ unattractive species,” in which — but it is a mat- 
ter of mere taste — I cannot agree. Its reddish orange colour on the dark 
rocks is to my eye most lively and pleasing, and more particularly so 
when other sponges are in its immediate proximity. At Ballyholme, 
Belfast Bay, within the space of a very few square feet, this species may be 
seen in small orange patches on the rock ; Hal. panicea in green masses, 
and by throwing aside the hanging fronds of Fucus nodosus (covered by 
their parasite Polysiphonia fastigiata ), Ptilota plumosa densely clothing 
the shaded rock is exposed to view, and on it the Grantia botryoides and 
G.foliacea grow plentifully, and the G. ciliata is sparingly seen. 
Although H. incrustans inclines generally to look directly down upon 
the water, or to grow on the under surface of rocks (see Grant, quoted in 
Johnst. B. S., p. 124), I find it also attached to their perpendicular sides, 
and when so, the “ fecal orifices ” are elevated, but not very much, above 
the surface. 
2 I 
