ASTEROIDEJE. 373 



Pennatula phosphorea (fig. 200, No. !); they are from two 

 to four inches long, of a purplish-red colour, except at the 

 base of the smooth stalk, which is a pale yellow, from, as 

 the fishermen say, this part being imbedded in the mud at 

 the bottom of the sea. They are built up in the same man- 

 ner as the former. The papillae on the back of the raehis, 

 and between the pinnae, are disposed in close rows, and do 

 not differ from the polype-cells except in size. The latter 

 are placed along the upper margin of a flattened fin ; they 

 are tubular, and have the aperture armed with eight 

 spinous points, which are moveable, and contract and 

 expand at the will of the animated inmates. The polypes 

 are fleshy white, provided with eight rather long retractile 

 tentacula, beautifully ciliated on the inner aspect with two 

 series of short processes, and strengthened moreover with 

 crystalline spicula, there being a row of these up the stalk, 

 and a series of lesser ones to the latter cilia. The mouth, 

 in the centre of the tentacula, is somewhat angular, 

 bounded by a white ligament, a process from which en- 

 circles the base of each tentaculum, which thus seems to 

 issue from an aperture. The ova lie between the mem- 

 branes of the pinnae ; they are globular, of a yellowish 

 colour, and by a little pressure can be made to pass through 

 the mouth. 



Dr. Grant writes : " A more singular and beautiful 

 spectacle could scarcely be conceived than that of a deep 

 purple Pennatula phosphorea, with all its delicate trans- 

 parent polypes expanded and emitting their usual brilliant 

 phosphorescent light, sailing through the still and dark 

 abyss, by the regular and synchronous pulsations of the 

 minute fringed arms of the polypes." The power of loco- 

 motion is doubted by other writers, and the pale blue light 

 is said only to be omitted when under the influence of 

 some painful irritation. 



In some genera, Virgularia mirabilis and pavonaria, to 

 which the name of Sea-rush has been given, the central 

 stem is from six to ten inches long (see No. 2, fig. 172). 

 Sowerby describes them as like a quill stripped of its feathers. 

 The base has some resemblance to a pen, as in the other 

 species, swelling a little from the end, and then tapering, 

 The upper part is thicker, with alternate semicircular pec- 



