594 ZOOPHYTES. 



GENUS IV. PENNATULA. LINN^US. 



Pennatufidce penniformes, pinnulis distichis, latis, et patentibus, mar- 

 gine superior e polypiferis ; axe osseo. 



Penniform or plume-shape, pinnules on opposite sides, broad and 

 spreading, with the upper margin polypiferous ; axis osseous. 



The Pennatulse differ from the Virgulariee in their stouter forms, 

 and broad spreading pinnules, which give a plume shape to the zoo- 

 phyte. The lower or posterior extremity is naked. The papillae have 

 generally a crenated anterior border, owing to the prominence of the 

 polyps. .The animals are similar in all essential points to the Alcyo- 

 nia. The axis is cartilaginous, or almost like bone. 



Several species of Penoatulffi have been observed to give off, when 

 alive, a phosphorescence of considerable brilliancy. 



This genus as used by LinnaBus included all the Pennatulida3; it 

 was restricted to its present limits by Cuvier and Lamarck. 



1. PENNATULA PHOSPHOREA. 



P. purpureo-rubra, stipite terete, carnosd, longiuscula, rachidis dorso 

 papillis crebris scabro, media sulcalo ; pinnularum margine caliculis 

 denlato-setaceis pectinato. 



Reddish-purple, basal portion terete, fleshy, and rather long ; back of 

 the rachis crowdedly scabrous with papillae, and sulcate down the 

 middle; margin of the pinnules pectinate, with dentato-setaceous 

 calicles. 



European seas. 



This is a common phosphorescent species, two to six inches long. 

 The axis is smooth, slender, and quadrangular, tapering at each extre- 

 mity, and often hooked. The plumose portion of the zoophyte is a 

 little more than twice as long as its greatest breadth. 



Penna marina, Bohadsch, Mar., Tab. 8, Pennatula pliosp/torea, Linn., ed. xii., 



fig. 5. sp. 2. 

 , Sibbald, Scot., ii. lib. tert., 28. , Ellis, Phil. Trans., liii., tab. 19, figs. 



