GEOLOGICAL SOCIETY OF DUBLIN. 
149 
I.-ZoOPHYTIC. 
Remains of some zoophy tiform animal, probably, judging from its form, 
Hydroid Sertularian. Two species are distinguishable, and have been 
named as following. One has been figured in Siluria, but both, up to 
this, are undescribed. 
1.— Oldhamia antiqua {Forbes). 
Polypidom cauliferous; stem percurrent filiform, -with short, alter¬ 
nate, fan-shaped branches, arranged at regular intervals. 
Occurs in beds, often some inches thick, massed together. There are 
two varieties of it found in Bray, the one having the fans so crowded as 
to render it liable to be mistaken for the next species, the other having 
the fans far apart and distinct. The beds in which this fossil occurs most 
abundantly at Bray, and all along the coast to Greystones, are greenish 
schist; it also occurs, but less abundantly, and smaller in size, in red 
schist. This latter may be a different species, being much smaller, and 
finer in texture. 
The only species which has as yet been detected at Howth. There 
are striking differences between the specimens from thence and those 
from Bray. They, however, appear to be identical with specimens from 
Carrick Mount, county of Wicklow, in the collection of the Geological 
Survey. 
2. — 0. radiata {Forbes). 
Polypidoms gregarious (?), short, many-branched; branches irregular, 
patent, thickened at the end, or many-branched, the branches sometimes 
arranged regularly in the form of a star. 
Occurs in much thicker beds than 0. antiqua. I am not quite sure 
whether the form from which the first part of the above description is 
taken belongs to this or a nondescript species: the more ordinary form 
has the characters described in the latter part of the description; the 
stars in the former measure 1*5 inch in diameter; in the latter 05 inch ; 
the stem appears to have been extremely short; in one specimen there 
appear to have been oviferous capsules. 
This is the most abundant species in the Bray beds; bed after bed 
of it occurring either as single beds, or in series of beds. One of these 
latter is fully five feet thick; the beds are either red or green schist. I 
have never met this at Howth, but it occurs abundantly, and very fine, 
at Greystones, county of Wicklow. 
II. Ankellidan. 
These exhibit themselves as— 
1st. Plattened, cylindrical, tortuous markings in the direction of the 
bedding, or nearly so; their structure ringed so that tearing them across 
gives the effect of a series of watch-glasses placed one within the other; 
evidently the exuviae of worms wandering through beds of muddy sand, 
and leaving behind them in their course the sand which had contributed 
vol. v_ peoc. soc. x 
