BY W. M. BALE. 779 



summit of each internode, 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. 

 Sarcothecse bithalamic, canaliculate, slender at the base and 

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

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

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

 each stem-internode. 



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

 tubular neck directed to one side. 



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

 (Mr. J. B. Wilson). 



The specimens of P. tripai'tita (which are among Dr. von 

 Lendenfeld's 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 

 l»ranches, 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 for"".', 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. 12-1.3). 

 Hydi'ocaulus 1^-2 inches in height, monosiphonic, sometimes 

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

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



