THE COLLECTION OS" MISS H. GATTT. 141 



deep brown colour, which contrasts with the lighter and more 

 transparent walls of the hypothecse and internodes, while its free 

 margin is further thickened into a prominent rim, which in 

 optical section has the appearance of a round knob turned 

 forward, or towards the cavity of the hydrotheca. The orifice of 

 the gonangium is encircled by a line of minute punctse. 



Notwithstanding these differences, I do not regard the distinc- 

 tion as sufficiently marked to justify us in viewing the West- 

 Australian form as specifically distinct from the Tasmanian. 



The specimen occurs creeping over the stems of a Gaulinia, 

 thus indicating a shallow-water habitat. Along this zosteraceous 

 plant its elegant plumes extend for several inches. 



Sertularia CRiisroiDEA, n. sp. (PI. Xyi. figs. 1, 2.) 



Trophosome. — Stem simple, springing at short intervals from a 

 creeping stolon, to which it is attached by a short spirally corru- 

 gated peduncle. Hydrothecse adnate to the internode by the 

 entire height of their epicauline side, the apocauline margin of 

 the orifice prolonged divergently upwards and deeply emarginate. 



Gonosome not known. 



Locality. Cape of Grood Hope. 



Sertularia crinoidea does not exceed y'g- of an inch in height. 

 The prolonged and deeply cleft apocauline margin of the orifice 

 confers on the hydrothecse of this minute Sertularia a form which 

 may be compared to that of a, mitre. The internodes are short, 

 and the pairs of hydrothecse closely approximate. The proximal 

 portion of the stem forms a distinct peduncle, which is sur- 

 rounded by a few spiral corrugations, and the creeping stolon 

 from which this arises has the inner layers of its walls marked 

 by closely-set transverse constrictions, which in optical section 

 are seen projecting into its cavity. 



The very short simple stems are closely set on the creeping 

 stolon, and each carries usually five or six pairs of hydrothecse. 

 Each internode with its pair of hydrothecse presents a symme- 

 trical and very elegant outline, and when viewed in the plane 

 common to the two hydrothecse, recalls the form of the flower in 

 certain lilies. 



No gonosome was developed on the specimen, which occurred 

 growing over the surface of a seaweed. 



Sertularia amplectens, n. sp. (PI. XYI. figs. 3, 4.) 

 Trophosome. — Stems slender, monosiphonic,pinnately branched. 

 Hydrothecse adnate to the internode for somewhat more than 



