212 Dr. W. C. M'Intosh on the Zoophytes of St. Andrews. 



Fam. 8. Sertulariidae. 



Genus Sertularella, Gray. 



Sertularella polyzonias, L. ; Hincks, Brit. H. Z. vol. f. 

 p. 235. 



Abundant in the deep water of the bay, generally attached 

 to the roots of other corallines. All the specimens seem true 

 to the description of the species ; at least there is no tendency 

 to wrinkles in the hydi'othecas so far as examined. 



Sertularella rugosa^ L. ; Hincks, Brit. H. Z. vol. i. p. 241. 



Common ; under stones near low-water mark, and thence to 

 deep water, on seaweeds, Flustra foliaceaj &c. 



Sertularella tenella, Alder ; Hincks, Brit. H. Z. vol. i. p. 242. 



In profusion on Sertularia abietina and other zoophytes from 

 the coralline ground. 



Genus DiPHASiA, Agassiz. 



Diphasia rosacea, L. ; Hincks, Brit. H. Z. vol. i. p. 245. 



Abundant in deep water on other corallines, such as Hydr- 

 allmania falcata, Thuiaria thuja, Halechim, &c. The speci- 

 mens are large and luxuriant. Mr. Hincks is right in stating 

 that the male gonothec^ have eight longitudinal ridges, and 

 not six as Dr. Allman says. 



Diphasia tamarisca, L. ; Hincks, Brit. H. Z, vol. i. p. 254. 

 Not uncommon in deep water attached to shells and stones. 



Genus Sertularia, Linn. 



Sertularia jpumila, 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 hydrothecge, 

 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. 



