326 Scientific Proceedings, Royal Dublin Society. 
position on the shell, so that it may receive the full benefit of the 
food-particles which may be in the current set up by the living 
mollusc, as has been shown by Canon Norman. it is a very rare 
species, and new to Ireland. It has previously been obtained by 
Canon Norman from about twenty miles north of Unst, in Scot- 
land, parasitic on the shells of Astarte sulcata and Dentalium 
entalis; and by Mr. Alder, from the coast of Northumberland, 
also on Dentalium entalis. The Irish specimens from Blacksod 
Bay were obtained at a depth of from six to eight fathoms. 
Eudendrium insigne, Hincks. 
In this minute species the stem is ringed throughout and not 
much branched. It is now recorded for the first time from Ireland, 
having been collected by the Survey from Lough Swilly at a depth 
of from eight to twelve fathoms. It is only known from a few 
English localities. 
Perigonimus repens, T'. 8. Wright. 
A rich supply of different forms of the genus Perigonimus has 
been collected by the Survey. It is a somewhat difficult group 
to study, especially from spirit material; and it is only by com- 
parison with an abundance of forms that reliable identifications 
can be obtained. ‘The limitations of the species are not well 
defined in the size, amount of branching, and the characters of 
the polypary. Some of the species have certainly been described 
from too limited a supply of material. 
A much branched condition of P. repens is represented on 
Plate xiv., figure 1. There are five distinct branches or bifur- 
cations, one of them bearing a characteristic gonophore. Others, 
arising from the same colony, were also elongated, but with- 
out any branching, exactly as represented in Alder’s drawing 
of the species reproduced by Hincks on pl. 16, “ Brit. Hyd. 
Zooph.” The polypary is thin and delicate, but less so proxi- 
mally. It is covered with a rather thick layer of a gelatinous 
substance, in which is embedded foreign matter, consisting mostly 
of fine mud. ‘The stems at their origin have two or three distinct 
