BY E. A. BRIGGS. 201 



each side, occupy a more or less erect position, although the abcau- 

 line two show a tendency to bend outwards. The back is entire. 

 There is no intrathecal ridg-e. The aperture between the hydro- 

 theca and the internode is surrounded by minute sharp denticles 

 projecting- into the hydrotlieca. Tliere are no septal ridges in the 

 internode. 



The mesial sarcotheca is l)ased on the much elongated proximal 

 part of the internode, and projects at a wider angle than the 

 hydrotheca, to the basal part of which it is adnate most of its 

 length, but Avith a short free projecting portion. The mesial sar- 

 cotheca is small, and stoj^s considerably short of the marg-in of the 

 hydrotheca. The terminal and inferior apertures are distinct, 

 though closely approximate. The terminal aperture is small and 

 circular. The lateral sarcothecse are adnate, saccate, with a circu- 

 lar sub-tubular orifice directed downwards from the hydrotheca 

 and outwards, and distinct from the wide lateral aperture. There 

 are three cauline sarcothecae; two on the anterior surface of the 

 rachis at the base of each hydrocladium, large and swollen, with 

 two circular orifices bordering the free margin ; the third is similar 

 to the laterals in shape and is situated at the back of each axil. 



Gonosome. — Unknown. 



Colour. — Light brown, stem and branches darker. 



Di'me7isions. 



Stem internode, length ... ... ... ... 0*71-0"78 mm. 



Stem internode, diameter 0-38-0-43mm. 



Branch internode, length .. 38 073 mm. 



Branch internode, diameter... ... ... ... 024-029mm. 



Hydroclade internode, length 0-33-0-36mm, 



Hydroclade internode, diameter ... 019-0 22mm. 



Hydrotheca, depth 0-23-0-24mm. 



Hydrotheca, breadth at mouth (lateral aspect) ... 0-19-0-2I mm. 



Anterior cauline sarcotheca, greatest width ... 0"14-017mm. 



The habit of the colonies is striking. The stems spring from a 

 dense mass of hydrorhizal filaments and either remain simple, or 

 towards their distal extremity give off, at irregular intervals, two 

 or three short peduncles. These spring from the front of the 

 hydrocaulus, and, at their origin, are directed forward, so as to 



