30 PLUMULARIA ATTENUATA. 



short peduncle, by which they sprnig from the axils of the pinnte, open- 

 ing on the summit by a wide oblique aperture. 



Off Alligator Reef, from a depth of 88 fathoms. 



This species grows in tufts, numerous undivided stems springing from 

 a common base. It is of a rather rigid habit; the pinnre 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. 



Trophosomc. — Hydrocaidus attaining a height of about two 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. Hydrothecte 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 Cojima, Cuba, from a depth of 450 fathoms. 



Phmmlaria macrotheca is remarkable for its long narrow hydrotheca}. 

 Its very slender pinnae are rather widely set upon the stem, which is fas- 

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

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



Plumularia attenuata. 

 PI. XVIII Figs. 5, 6. 



Trophosome. — Hydrocaulus branched, fascicled below ; piiuite alternate, 

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

 node; internodes of pinnae elongated, becoming abruptly slender in the 

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

 basal portion. 



Supracalycine nematophoi'es springing from tooth-like processes which 



