Mr. A. H. Hassall’s Catalogue of Irish Zoophytes. 167 
believing in their animal nature from their structure and che- 
mical composition. 
I have here to acknowledge the obligation I am under to 
Dr. Johnston* of Berwick, who kindly afforded me the benefit 
of his experience wherever I entertained doubts as to the iden- 
tity of any of the species mentioned, and from whose assist- 
ance, in this particular, Iam enabled to present this Catalogue 
with the greater confidence. 
RADIATED ZOOPHYTES. 
Order I. ZOOPHYTA HYDROIDA. 
TUBULARIAD 2. 
TuUBULARIA. 
Tubularia indivisa.—Dublin bay; not common. 
T. ramea. This is one of the most delicate and arborescent of the 
corallines, exactly resembling a miniature tree. The ultimate tubes 
have four or five distinct rings at their base. Polypidom about six 
inches in height. 
On shells from deep water; rare. Blackrock, Dublin bay. 
SERTULARIADA. 
THOoA. 
Thoa halicina. A variety of T. halicina is frequently met with- 
distinguished from the ordinary specimen by its irregular mode of 
branching. 
Dublin bay ; common. 
T. Beanii. Of this extremely elegant zoophyte I have met with 
several specimens, averaging from four to six inches in height. There 
is a great resemblance between Thoa Beanii and the preceding, with 
the variety of which it may be readily confounded, particularly when 
deprived of its very characteristic vesicles. It may, however, be 
known from it by the branches passing from the main stems nearly 
at right angles, but at unequal intervals, and by its being érregu- 
larly ringed, having also a joint between each cell, in which re- 
spect it agrees with T. halicina. 
SERTULARIA. 
Sertularia polyzonias. Between this and the one following there 
is a manifest relation. They are both usually found upon Flustra 
foliacea, though not confined to it. 
Killiney bay; not common. 
S. rugosa.— Kingstown ; not common. 
S. rosacea, Usually found as a parasite on S. cupressina and S. 
_Tamarisca, particularly on the former. 
Dublin bay ; abundant. 
* T have followed the Arrangement and Nomenclature given in Dr. J.’s 
admirable work on British Zoophytes. 
