Sept. 1, 1869.] 



HARDWICKE'S SCIENCE-GOSSIP. 



201 



duccd freely, the male only one- third the size of the 

 female, and bluntly toothed at the apex ; the 

 female obovate and divided by longitudinal lines 

 into four lobes. This species is almost confined to 

 the coasts of Devon ami Cornwall, in deep water. 



Fig. 153. Diphasia pinnata, magnified. 



Diphasia pinaster, as now understood, includes 

 also two species of Johnston, the male Sertuiaria 

 pinaster, and the female Sertuiaria margareta. It 

 attains from two to six inches in height, and is of a 

 light horn colour. The cells or calycles are cylin- 

 drical, the upper half very abruptly turned outwards, 

 so as to cause a fold at the angle (fig. 151). The 

 male capsules are ovate, and almost quadrangular in 

 the upper portion, with a spine at each angle. The 

 female capsule is oval, with four longitudinal ridges, 

 and about eight divergent spines in two series on 

 the upper half (fig. 151, a). It is not an uncommon 

 species, and seems to be well distributed. 



Fig. 154. Diphasia pinaster, a. calycles; b. female capsule. 



The true Sertularias may be grouped in a similar 

 manner. Four species have the cells more or less 

 opposite in their arrangement, and only one of these 



has the branches regularly pinnate. This is S. 

 filicula. Two species are very small and but slightly 

 branched, and the other {S. operculata) is one of the 

 commonest of zoophytes, and branches much and 

 irregularly. The " Sea Hair Coralline " {Sertuiaria 

 operculata) is very slender and delicate, the opposite 

 calycles divergent, ending in a sharp point, with a 

 small intermediate tooth (fig. 155). The capsules 



Fig. 155. Sertuiaria operculata. a. natural size; b. magnified. 



are pear-shaped and large, with a circular lid 

 (fig. 156). It is parasitic on seaweeds a little below 

 low-water mark, and may nearly 

 always be picked up on the 

 shore. 



The "Sea Oak Coralline" 

 {Sertuiaria pumila) is seldom 

 more than half an inch in height, 

 and yet it attaches itself in such 

 clusters to some of the larger 

 seaweeds as almost to cover 

 their stems. The calycles are 

 in pairs forming a V-shaped 

 figure. The capsules are ovate, 

 with a tubular rim. This and 

 its ally, Sertuiaria gracilis, are Fig-. 156. Capsule of 



the tWO Small and slightly Sertuiaria operculata. 



branched species above alluded 

 to. The latter is not more than half the size of its 

 companion species, more delicate, and quite trans- 

 parent. The cells are alike in form, but smaller. 

 The capsule has a narrower neck and is less rimmed. 

 Both are equally common on seaweeds and other 

 zoophytes. 



The " Fern Coralline " {Sertuiaria filicula), as 

 already observed, has feathery branches, and oppo- 

 sitely arranged cells, or calycles (fig. 158). It is more 

 slender and delicate than the majority of the pinnate 



