BY W. M. BALE. 779 



summit of each inter-node, divided into alternate long and short 

 internodes, of which only the former bear hydrothecse. Hydro- 

 thecse small, cup-shaped, much expanded upwards, adnate up to 

 the margin, aperture nearly at right angles with the pinna. 

 Sarcothecae bithalamic, canaliculate, slender at the base and 

 moveable ; one below each hydrotheca and one at each side above 

 it, one between every two hydrothecae, on the intermediate inter- 

 node, one at the base of each pinna, and one on the lower part of 

 each stem-internode. 



Gonothecae borne in the axils, rather slender, fusiform, with a 

 tubular neck directed to one side. 



Hab. Timaru, N.Z. (Dr. von Lendenfeld) ; Port Phillip Heads 

 (Mr. J. B. Wilson). 



The specimens of P. tripartite, (which are among Dr. von 

 LendenfekTs types) do not possess any features by which they 

 might be distinguished from P. setacea, the tripartite form of the 

 hydranth being only an occasional feature. The hydrophyton is 

 normally unbranched, but some of the shoots bear several lateral 

 branches, which are very peculiar in their origin, since they 

 commence as ordinary pinnae or hydrocladia, and only become 

 modified into branches beyond the first internode, which bears a 

 hydrotheca and nematophores in the usual way. Mr. Hincks 

 mentions a branched variety of P. setacea as occurring in Britain, 

 but does not state whether the branches are modified from hydro- 

 cladia as in the present case. 



Plumularia Wattsii has hydrocladia with the hydrothecse and 

 sarcothecae similar in form and arrangement to those of the 

 present species, but the pinnate shoots, instead of springing 

 directly from the hydrorhiza, are borne on a long slender jointed 

 stem. 



PLUMULARIA TURGIDA, n.sp. 



(Plate XX., figs. 12-13). 



Hydrocaulus 1J-2 inches in height, monosiphonic, sometimes 

 branched ; pinnaa alternate, not close, one borne near the summit 

 of each intemode, divided into alternate long and short internodes, 



