28 
MARINE FAUNA OF ST. ANDREWS. 
Genus Sertularia, Linn. 
Sertularia pumila, L. ; Hincks, Brit. H. Z. vol. i. p. 260. 
This is the common Sertularian under stones in rock-pools 
at and near low-water mark at St. Andrews; but it is less 
luxuriant than on the Fuci of the western coasts. It forms 
a miniature forest on the under surface of the stones in quiet 
places, and is a favourite haunt of Eolis viridis and other 
Nudibranchs. It presents the peculiarity in such situations 
that the stem is not always contracted above the hydrotheese, 
but not unfrequently these follow each other without the con¬ 
striction. In some preserved specimens the hydrothecse con¬ 
tained a number of large nucleated cells, having apparently a 
thickened and regularly crenated cell-wall; these cells varied 
in size; and some also occurred in the centre of the stem. 
Sertularia operculata , L.; Hincks, Brit. H. Z. vol. i. p. 263. 
Not uncommon; on seaweeds at and beyond low-water 
mark, but chiefly procured on the West Sands after storms. 
Its comparative scarcity is in marked contrast with its profu¬ 
sion on our western coasts, where almost every laminarian root 
and stalk are clothed with dense tufts. 
Sertularia filicula , Ellis and Solander; Hincks, Brit. H. Z. 
vol. i. p. 264. 
This, perhaps, is the most abundant Sertularian next to 
S. abietina from deep water. Dried specimens, when carefully 
laid out, show a somewhat rectangular arrangement of their 
terminal branches. Good examples have also been procured 
from the stomach of the cod. 
Sertularia abietina , L.; Hincks, Brit. H. Z. vol. i. p. 266. 
Very common, and occasionally reaching the height of 
9 inches; fine tufts occur on Mytilus modiolus. This species 
is a favourite seat of many parasites, such as other hydroid 
zoophytes, calcareous corallines, Spirorbis, Alcyonidium , 
Coppinia , &c. From its attachment to living mollusca 
(.Anomia and others) it is not unfrequently swallowed by the 
cod. 
