HYDROIDA. 
457 
Magilligan, Mr. Hyndman : here and on the Dublin coast it grows most 
luxuriantly, occasionally attaining a foot or a little more in height ; and 
is often densely branched, in which state, and when uninjured, it is a 
very beautiful object. 
Clew Bay, W. T. 1840. 
P. cristata, Lamx. 
Youghal, Dublin Bay, Miss Ball. Waterford coast, Miss A. Taylor. 
Ballysodare Bay, Co. Sligo, Mrs. Hancock. Down and Antrim coasts, 
Alum Bay, Isle of Wight (in profusion, Sept. 1841), W. T. ; all my spe- 
cimens from these localities are on Halidrys siliquosa. A. Plumularia in 
my collection, obtained at California by Dr. Sinclair, seems in every re- 
spect identical with native specimens of P. cristata. 
P. pennatula, Ellis and Soland. 
Specimens of this rare and beautiful species profusely invest about six 
inches of the stem of a Laminaria digitata obtained in a fresh state by 
Miss M. Ball at Youghal in 1837. It must rather, I presume, have been 
owing to the East Indies being the locality whence the specimens de- 
scribed by Ellis and Solander were brought, than to any fault in Fleming’s 
description (which seems as good as one so brief could be), that led some 
authors on the continent to attribute it to other species. The Irish spe- 
cimens correspond with the descriptions in the works of Ellis and So- 
lander, Fleming and Johnston, and with the figures in the first and last — - 
some of them are 4^ inches in height. 
Found also at Roundstone by Mr. M‘Calla. 
Dec. 29, 1851. — I saw a very fine group of this species to-day in Miss 
Ball’s collection. It, with several other groups, was found at Ballycotton 
(Co. Cork) in August last by Miss Gaggin. The piece I saw appeared 
attached to the stem of a common Laminaria (tangle). 
P. pinnata, Lamx. 
In Mr. Templeton’s collection there are specimens of this Plumularia , 
although it is not recorded by him. Dredged in 8 fathoms water in Bel- 
fast Bay. Dublin Bay, 1834, Prof. Harvey. Youghal, Miss Ball. Fine 
specimens, from 4 to 6^- inches in height, dredged upon the same day 
(June 15, 1842) in Red Bay, Co. Antrim ; and about Sana Island in 40 
fathoms, on the neighbouring coast of Scotland, where very fine spe- 
cimens were dredged by Mr. Hyndman. 
My specimens, with vesicles and agreeing in all respects with Dr. J.’s 
S. pinnata , except in three branches springing from each joint, I find is 
perfectly identical with the fig., Dr. Ellis, Coral., pi. xi. fig. A., in having 
only one pinna springing from each joint. 
P. setacea , Lamx. 
Antrim and Down coasts, Clew Bay, Co. Mayo, W. T. Ballysodare 
Bay, Co. Sligo, Mrs. Hancock. Glendore, Co. Cork, Prof. Allman. Spe- 
cimens in Mr. Hyndman’s collection, dredged at Donaghadee, July 12, 
1842, are remarkably fine. They densely invest the stem and main 
branches of a specimen of Halidrys siliquosa, throughout about a foot of 
its length, and from every plume throughout the mass issues a series of 
vesicles closely placed together from the base to near the summit ; these 
vesicles generally, if not always, spring from the upper side of the stem. 
Among Zoophytes given me by the late Archibald Menzies, Esq., were 
