TOPOGRAPHICAL, ECOLOGICAL AND TAXONOMIC NOTES. 341 



la the peaty soil on the edge of the basin, a slender 

 stemmed trailer, Oxyloblum cordifolium Andr., has spread 

 an intricately woven canopy over the cyperaceous growth, 

 extending in a narrow ribbon-like formation for a consider- 

 able distance along the margin. At Little Bay, individual 

 plants of this species are plentiful in the shallow soil 

 trenches on the rocky hillside, but the environment is 

 unfavourable to luxuriant growth, and the plants rarely 

 cover an area greater than one to two feet in diameter # 

 It is endemic in New South Wales, and has an ascertained 

 coastal range from the southern side of Port Jackson to 

 Milton. 



Three Ferns, each with a wide extra Australian range, 

 have formed small exclusive colonies in the partly sub- 

 merged area. Of these, Gleichenia dicarpa R. Br., has 

 bound its members by knitting their wiry stemmed fronds 

 into a tangled network above, and connecting them by 

 creeping rhizomes below the ground line. The rhizomes 

 of this fern are exceptionally sensitive to injury and rarely 

 survive disruption. A similar connecting device is adopted 

 in a modified form by Histiopterls incisa (Thunb.) J. Sm., 

 which does not resent removal to the same extent as the 

 Gleichenia. The third member of the group, Blechnum 

 serrulatiim Rich., has an erect habit, the fronds rising 

 from a short, truncate, horizontal rhizome in plume-like 

 tufts. 



Of the smaller growths in the basin the weak stemmed 

 Boronia parviflora Sm., straggles among the Sedges, the 

 plants, usually solitary, ranging between the flooded area 

 and the margin, and rarely venturing beyond the peaty soil 

 of the bog. Its frequent associate, the rosetted Goodenia 

 stelligera R. Br., is almost as strictly limited in its choice 

 of habitat, and the slender Schcenus apogon Roem. and 

 Schult., their occasional neighbour, may be placed in the 

 same category. In this station Schcenus brevlfolius R. Br., 



