28 MARINE FAUNA OF ST. ANDREWS. 



Genus Seetularia, 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 hydrothecse, 

 but not unfrequently these follow each other without the con- 

 striction. In some preserved specimens the hydrothecEe 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 (yperculata, L. ; Hincks, Brit. H. Z. vol. i. p. 263. 

 Not imcommon; 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 Jilicula, 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 occui- on Mytilus modiolus. This species 

 is a favourite seat of many parasites, such as other hydroid 

 zoophytes, calcareous corallines, Sj^irorbis, Alcyonidium, 

 Goppinia, &c. From its attachment to living mollusca 

 [Anomia and others) it is not unfrequently swallowed by the 

 cod. 



