318 A. A. HAMILTON. 



alone surviving. On the newly formed bank the Fescue 

 has erected an irregular system of elongated bands running 

 parallel to the beach, stretching ribbon-like, along the 

 otherwise bare sand and creating a series of ridges, whose 

 confluence, when consummated, will form the nucleus of the 

 landward embankment of the dune valley which will even- 

 tually be developed. In this region also the Fescue is 

 unsupported, no other species with the qualification neces- 

 sary for existence in this unstable environment having yet 

 appeared, but its associate the Spinifex, is moving out from 

 the embankment plateau to connect with the Fescue, and 

 assist by retaining the bank which the latter is building. 



At the southern boundary of the excavation, a second 

 similar breach occurs. On the frontal slope of the embank- 

 ment, south of these gaps, which here enters the protected 

 zone under the influence of the shelter provided by the 

 northern headland of Freshwater Beach, the succulent 

 trailer Seneclo spathulatus A. Rich., has formed a chain of 

 mats several hundred yards in length, on horizontal ridges 

 at a relatively even elevation above the strand. This 

 species has been collected as far north as Port Stephens, 

 but is more securely established south of Port Jackson, and 

 rarely leaves the vicinity of the strand. It responds 

 quickly to a halophilous environment, modifying its leaf 

 structure chiefly in the direction of diminished length, and 

 increased rotundity and thickness, as the soil salinity is 

 increased. 



A considerable area on the rearward slopes is occupied 

 by a dense coppice of the "Coast Tea-tree," in whose 

 darkened precincts a colony of Podocarpus spinulosa is 

 established. The Podocarpus is an exceptionally rigid 

 species, and does not exhibit a marked difference in either 

 structure or habit when growing in this dense shade, to 

 that maintained on the open hillside subject to direct 



