196 Rev. T. Hincks's Contributions towards a 



ferous tufts are borne, if not exclusively, at least in a very- 

 great majority of cases, on the shorter only. These diffe- 

 rences are interesting, but they are not of very marked signi- 

 ficance. 



The segments composing the stem are clearly abortive 

 zooecia ; morphologically the stem is the equivalent of such 

 structures as the stolon in the genera Aetea and Eucratea. 

 In Stirparia glabra a large number of tubular fibres are given 

 off from the lower internodes, originating in each case a little 

 above the base ; these, as they pass downwards, become 

 closely attached to the stem, which is often thickly coated 

 with them. At the bottom of the stem they become free and 

 form a multitude of spreading rootlets. 



Stirparia glabra, n. sp. (PL VI. fig. 2.) 



Stems erect, calcareous, smooth, more or less branched, at- 

 taining a height of about | inch, made up of alternate long 

 and short segments, separated by corneous joints ; the larger 

 widening somewhat towards the top, and also slightly enlarged 

 just above the base ; surface smooth, polished, traversed on two 

 faces by a fissure, which widens out towards the top, and is 

 filled in by a transparent membranous (?) covering ; the 

 interposed smaller segments (about one third the length of the 

 larger) rounded off below, at the top an obliquely truncate 

 orifice on one side (from which celliferous tufts may originate), 

 also furnished with fissures ; stems attached by means of 

 numerous tubular fibres given off from the inferior internodes ; 

 celliferous branches given off from the lateral opening at the 

 top of the shorter segments, forming more or less flabellate 

 tufts ; the primary zooecium in each tuft short, broadly tur- 

 binate, with a large terminal aperture and a number of mar- 

 ginal spines ; from this two branches arise, which soon bifur- 

 cate. Zooecia in two lines, alternate, suberect, turbinate ; 

 aperture occupying less than half the length of the cell, turned 

 very decidedly inwards towards the central line, wide above, 

 contracted below ; margin raised, thin, the upper lip often 

 extended into a spinous point on the outer side ; four or five 

 long, curved spines above, sometimes placed a good way 

 down on the dorsal surface, a single spine near the bottom of 

 the area at one side, tall, curved, bending inward ; portion of 

 cell below the aperture slender, tapering downward ; a 

 minute, articulated avicularium on the margin of the area at 

 the bottom. Ocecium (?). 



Loc. Geraldton, Western Australia (Miss E. Gore). 



The avicularium is very sparingly present in the speci 



