EEPORT ON THE PENXATULIDA. 199 



Of PeniKititla phiifphoren. to which the Oban specimens clearly 

 belong, three chief varieties are mentioned by Kolliker : — 



a. P. phogphorea, var. ajinu.ttifoUa. Leaves long and narrow ; polype 

 heads few in number, and wide apart. 



b. /'. plioaphorea, var. Jancifolia. Leaves lanceolate ; polype heads 

 numerous and placed close together. Of this variety, to which the 

 Oban specimens are to be referred, Kolliker distinguishes four sub- 

 varieties. 



c. I'. pJiosphorea. var. aculeata. Leaves narrow and some distance 

 apart ; on ventral side of rachis, four to six rows of prominent spines, 

 connected with the zooids. 



Habits— 



1. The Xiiiiiral Po<ition of Pennatuhi. — On this point the various 

 zoologists who have described Pciiiidtula from living specimens differ 

 remarkably. 



Ellis,* speaking of Peitnatula, says : — " This genus of animals differs 

 remarkably from all the other Zoophytes by their swimming freely 

 about in the sea, and many of them having a muscular 

 motion as they swim along. I know of none of them 

 that fix themselves by their base, notwithstanding what has 

 been wrote." Other anatomists have described Pennatula as having 

 the power of swimming freely, and Dr. Grant goes so far as to say 

 that " a more singular and beautiful spectacle could scarcely be 

 conceived than that of a deep purple P. phosphorea, with all its delicate 

 transparent poh'pi 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 

 whole polypi.'' 



This is doubtless very beautiful, but unfortunately does not appear 

 to have the smallest shred of direct evidence in its support. Ii is 

 difficult to get to the origin of these accounts, but this is apparently to 

 be found in an observation of Bohadsch, whom we have already 

 mentioned as the first describer of Funiculina. 



Bohadsch describes Pennatula as a deep-sea animal, which is 

 sometimes caught " with other fishes." He notes its phosphorescent 

 properties, to which we shall refer below, and then says t that on one 

 occasion, in the year 1749, while sailing in the Mediterranean, he 

 observed some phosphorescent body about four feet below the surface 

 of the water, and being at that time " in historia natural! miuime 

 versatus " he asked the sailors what it was, and they told him that it 

 was Penna, i.e., a sea-pen or sea-feather. 



Now Ellis avowedly obtained the greater part of his information 

 concerning Pennntida from Bohadsch, and there is much reason for 

 thinking that Dr. Grant's account is based on that of Ellis, so that it 

 would really seem as if Dr. Grant's glowing description rests merely on 

 a solitary observation made by a man who speaks of himself as 



* Ellis and Solauder, Natural History of Zoophytes, 17SG. p. GO. 

 1 Bohadsch " De quibusdam aniuialibus mariuis," 1761, p. 107. 



