200 



HARDWICKE'S SCIENCE-GOSSIP. 



[Sept. 1, 1869. 



Mr. Hincks lias followed is the one we feel most 

 disposed to adopt even fur this superficial review. 



Fig. 150. Sertulariella rugosa, magnified, a. capsule. 



In the Diphasia group the calycles are more or 

 less decidedly opposite, as they are also in half the 

 species included in Sertularia, but the mouths of 

 the cells in the former are either entire, or only 

 obscurely toothed, whilst in the latter either two- 

 lipped or pointed. The capsules differ in the two 

 genera, although this character is of very little ser- 

 vice in determining empty skeletons. In Dipkasia 

 there is a spherical pouch in the upper portion of 

 the'capsule which is absent in Sertularia. ■ 



Fig. 151. Diphasia rosacea, natural size. 



Of. the seven species of Diphasia, two are irregu- 

 larly branched, two irregularly pinnate, and three 

 decidedly pinnate. Of those branching irregularly, 

 the smallest aud most delicate is the "Lily Coral- 

 line " {Diphasia rosacea). The shoots are very 

 slender and delicate (fig. 151), chiefly parasitic on 

 other zoophytes. Its texture is thin, and the cells 



are subject to folding and wrinkling when dry on 

 this account (fig. 152, a). The capsules have eight 

 longitudinal ridges, ending in as many projections 

 at the apex (fig. 152, h, e). This is usually minute, 

 seldom exceeding one or two inches in height. 



The other irregularly branched species is the 

 "Sea Tamarisk" {Diphasia tamarisca). It is of a 

 robust habit, and often of a large size. The cells 



Fig-. 152. Diphasia rosacea, magnified, a. calycles; I. male 

 capsule ; c. female capsule. 



have the upper half diverging, with a three-toothed 

 aperture. The male capsules are the smallest, and 

 somewhat heart-shaped, generally arranged in rows. 

 The female capsules are larger, and much lacerated at 

 the mouth. This species occurs on shells, &c, in 

 deep water, and is not very common. 



The irregularly pinnate species are Diphasia 

 attenuata and Diphasia fallax, neither of which is 

 particularly common. The former bears some re- 

 semblance to the Lily Coralline, save that it is of a 

 firmer texture, and the cells do not shrivel in dry- 

 ing. The capsules are strongly spiny at the apex, 

 with six longitudinal ridges. Generally parasitic 

 on other zoophytes. 



Diphasia fallax is feathery in its ordinary con- 

 dition, and usually bears a number of curled tendrils. 

 The steins are thick and dark coloured, with plumose 

 branches. The calycles are tubular and diverging ; 

 the capsules elongated, and surmounted by four 

 stout spines. Hitherto found only on our northern 

 coasts, attached to other zoophytes. 



Of the three remaining species, which have regu- 

 larly pinnate branches, Diphasia alata is rare. The 

 cells are very small and peculiar, with the upper 

 portion projecting abruptly. The other two are 

 Diphasia pinnata and Diphasia pinaster. 



The two forms described by Johnston and others 

 as Sertularia pinnata and Sertularia nigra are now 

 admitted to be male and female of D. pinnata. 

 The height is often six inches or more, and of a dark 

 colour when dry. The cells or calycles are rather 

 small, springing but little from the stem, with a 

 wide even mouth (fig. 153). The capsules are pro- 



