SU W. M. Bale : 



Plumulakia kvekta JM. and T. (Plate XVIL, Fig. 2). 



riui/mlaria evtrta, Mulder and Tiebilcock, Geel, Nut. (2), 

 iv., 1909, p. 31, 1)1. i., fig. 5. 



Hydiocaulus inoiiosiplionic, pinnate, lower part with stout 

 perisarc, divided by indistinct transverse joints at irregular in- 

 tervals, and bearing sarcothecae only; upper part thin, divided 

 by long oblique joints into internudes, each bearing a hydroiladium 

 and a hydrotheca. Hydrocladia alternate, the first internode (or 

 two internodes) very short, without appendages, the rest alternately 

 long and short, only the former bearing hydrothecae. 



Hydrothecae swollen and rounded below, strongly contracted on 

 the adcauline side a little below the aperture, which is entire and 

 slightly everted at the back. 



Sarcothecae bithalaniic, canaliculate, one below each hydrotheca 

 and two lateral above (pedunculate), one midway between every two 

 hydrothecae, on the intermediate internode (or, on the stem, on the 

 same internode as the lower), tAvo in line on each of the lower 

 stem-internodes, and a few on the hydrorhiza; those in front of 

 the hydrothecae stout and fixed, the rest moveable. 



Gonosome ? 



Loc. — Torquay, Vic. (M. and T.). 



Readily distinguished by the peculiar form of the hydrothecae. 

 These have the adcauline side, where it is recurved under the everted 

 margin, much thickened and in certain positions of the hydrotheca 

 it looks like an intrathecal ridge. 



Most commonly the intermediate internodes on the pinnae are 

 distinct, but sometimes the nodes are wanting, so that the superior 

 sarcotheca is on the hydrothecal internode, and this is normally 

 the case with the stem. The robust lower part of the stem, with its 

 transverse nodes, contrasts strongly with the delicate oblique- 

 jointed upper part, which, in the only specimen I possess, is only 

 about half the total height (5 mm.). I quote from Mulder and 

 Trebilcock in regard to the sarcothecae of the lower stem, and of 

 the hydrorhiza, which I have not seen. On the hydrocladia the 

 first internode after the basal ones supports a sarcotheca only. 



Plum UL ARIA balei Bartlett. (Plate XVII , Fig. 6). 



Plurtmlaria halei, Bartlett, Geel. Nat. (2), iii., 1907. p. 65, 

 fig. — . Mulder and Trebilcock, Geel. Nat. (2), iv., 

 1909, p. 29, pi. i., figs. 1-3. Briggs, Records Aust. 

 Mus., xii., 1918, p. 41, pi. v., fig. 8-10. 



