Manchester Memoirs, Vol. Ixii. (191 7), No. 4 15 



Pennatula fimbriata, Herklots. 



Filaments are present, being- in some zooids slightly convoluted 

 and in others practically straight ; in the latter they extend in 

 some cases as far as 0.064 m.m. beyond the lower edge of the 

 stomodaeum. 



P. grandis, Ehrenberg ( = P. borealis, Sars) . 



In the normal siphonozooids large thick and much coiled fila- 

 ments are present ; mesozooids are also present, occuring on the 

 dorsal rachis at the edge of each leaf. 



P. Murrayi, Kolliker. 



Mesenteric filaments are absent in the siphonozooids, but the 

 species resemble P. grandis in having mesozooids, on being 

 found at the edge of each leaf, in the same position as in the latter 

 species. 



P. phosphorea, Linnaeus. 



Filaments are present, being long, straight and rather slender : 

 maximum breadth 0.032 m.m. , length up to 0.56 m.m. This con- 

 firms the observation of the Marshalls (1882, p. 46). 



P. RUBRA, Ellis. 



The filaments are similar in size to those in the siphonozooids 

 of P. phosphorea. In a few of the zooids, however, I was unable to 

 find them ; it is possible they may have been accidentally dissected 

 away with the mesodermal tissue in making preparations, or may 

 actually have been present but obscured by mesodermal fleshy 

 tissue. As the number of zooids in which filaments were not observ- 

 ed was comparatively small, the point is of little importance. 



It may be noted here that in a surface examination of pieces of 

 P. rubra from the Bay of Naples, I saw no evidence of the large 

 zooid near the dorsal edge of the leaf which was described by 

 Kiikenthal and Broch for a specimen obtained from the Indian 

 Ocean (1911, p.383). 



Leioptilum quadrangularis, Moroff. 



The siphonozooids crowded on the dorsal side of the rachis and 

 between the leaves, bear mesenteric filaments. Their presence is 

 of interest in view of the fact that Kolliker found no filaments in 

 L. tmdulatum, Verrill, from California and Mexico. Of Leiop- 

 tilum and Sarcophylum this author says "In einem andern Punkte 

 stimmen jedoch beide Gattungen iiberein, namlich in dem Mangel der 

 Mesenterialfilamente in den Zooiden. Von den lateralen Zooiden 



