30 PLUMULARIA ATTEXUATA. 



short peduncle, by which they spring from the axils of the pinna?, open- 

 ing on the summit by a wide oblique aperture. 



Off Alligator Reef, from a depth of 88 fatliouis. 



This species grows in tufts, numerous undivided stems springing from 

 a common base. It is of a rather rigid habit ; the pinnae are close set ; 

 besides the nematophores of the pinnae we find on each internode of the 

 stem two large, alternately placed, solitary nematophores, and two pairs 

 of nematophores which are borne by the lateral process on which the 

 hydrothecal ramulus is supported. 



Plumularia macrotheca. 

 PI. XVIII. Figs. 3, 4. 



Trophosome. — Hydrocaulus attaining a height of about tw^o inches, simple, 

 fascicled, springing from an entangled mass of fine tubular filaments ; pinnae 

 very slender, alternate, composed each of a succession of long internodes 

 alternating with short ones, each of the long internodes bearing a hydro- 

 theca. Hydrothecae deep, tubular, with very slightly everted margin. 

 Supracalycine nematophores springing each from a short process which pro- 

 jects from the long internode, just below the margin of the hydrotheca, 

 one mesial nematophore carried by the same internode at the proximal 

 side of the hydrotheca, and another on each of the short internodes. 



Gonosome not known. 



Off Cojiiiia, Cuba, from a depth of 450 fathoms. 



Plumularia macrotheca is remarkable for its long narrow hydrothecie. 

 Its very slender pinnao are rather widely set upon the stem, which is fiis- 

 cicled, and, like other fascicled stems, resolves itself below by the separation 

 of its component tubes into a loose plexus of hydrorhizal filaments. 



Plumularia attenuata. 

 PI XVIII Figs. 5, 0. 



Trojy/iosome. — Ilydrocjiulus branched, fascicled below ; pinna? alternate, 

 each arising from a point of the stem close to the distal end of an inter- 

 node; internodes of pinna? elongated, becoming abruptly slender in the 

 distal two thirds of their length. Hydrothecic small, borne by the thicker 

 basal portion. 



Supracalycine nematophores springing from tooth-like processes which 



