PLUMULAllIA CATHAKINA. 301 



the base of the cup and the adjoining nematophore. The 

 male and female are dissimilar, and are intermingled not 

 only on the same shoot but on the very same pinna. The 

 female are relatively very ample. The oblique terminal 

 aperture is closed by an operculum, which is not cast off, 

 but remains attached at one point as by a hinge. The 

 central column bears a single sporosac, which 

 becomes terminal and occupies the upper Fig. 35. 

 portion of the cavity. One ovum, so far as 

 I have observed, is produced in each. In 

 the male, which is slender and comparatively 

 small, a mass of close granular matter, cor- 

 responding in shape with the capsule, extends 

 from the base to the top (Woodcut, fig. 35). 



P. Catharina grows in dense clusters, and 

 attains a height of 3 or 4 inches. 



A very curious and beautiful variety occurs in which the 

 erect stem is wanting, and simple shoots, exactly re- 

 sembling the pinnse of the ordinary form, are given off 

 directly from the creeping fibre. In this condition the 

 entire aspect of the zoophyte is so completely changed that 

 it might pass for another species. I have little doubt, 

 indeed, that the obscure Sertularia secundaria of Cavolini 

 is neither more nor less than the stemless form of P. 

 Catharina, or of some kindred species ; and the hydroid 

 described by Dana* under the name of Antennularia 

 cyathifera is evidently something of the same kind. 



The creeping variety of P. Catharina is of a delicate 

 citron-colour when living ; it is found with reproductive 

 capsules. 



This species was named by Dr. Johnston in honour of 

 his wife, to whom zoophytologists are under lasting obli- 

 gations for the drawings (many of them could hardly be 

 * United States Exploring Expedition : Zoophytes. 



