BY A. A. HAMILTON. 173 



moni/olius R.Br., (13; 1915, p. 118), and Hakea puyioni/'ormis 

 Cav., (I.e., p. 289) the latter species being also used to illustrate 

 ecological, varietal effects (/.c). 



The leaves of Petrophila pulchella R.Br., P. pednncidata R.Br. 

 and P. sessUis 8ieb., are difficult to separate, and similarity 

 exists between the leaves of all three, and Isupocjon, anethij'olius 

 R.Br. (13; 1915, p. 4 19). 



The genus Persoonia provides a foliar range from the acicular 

 leaves of P. piuifolia R.Br., to those of the exceptionally large, 

 broad, flat leaves of P. salicino, Pers. The latter species offers a 

 wide range of leaf- variation (13; 1914, p. 648, as opposed to the 

 similarity existing in the foliage of P. 'media R.Br., and P. 

 curiiifolia A. Cunn, the length and venation of the leaves, (char- 

 acters used to separate the two latter, 4; v., pp. 391-392) showing 

 inconstancy. 



The Banksias exhibit a transformation in leaves from B. 

 ericifolia L., to B. spinulosa Sm., and B. maryinata Ca,v . , leaving 

 the systematist occasionally in doubt as to which species he 

 should refer contiguous examples, the marginal toothing, and 

 size of the leaves showing many irregularities. A series of 

 leaves of B. marginata is figured on the plate illustrating that 

 species (10; ii., p-12) showing a number of form.s, with a con- 

 siderable range of variation. Similarity, on the other hand, 

 between the leaves of B. serrata L., and those of ^. ceynula R.Br., 

 is very pronounced. 



Examples of Conospermum taxifolium Sm., and C. ericifolium 

 Sm.,(13; 1914, p. 325) demonstrated the difficulty of separating 

 these two species on leaf-characters. The two species of Syni- 

 jjhyonema (endemic in New South Wales) are separated chiefly 

 on the foliage, which is largely influenced by environment, the 

 swamp-form of S. montmium R.Br., on the Blue Mountains, fre- 

 quently pi'oducing leaves the counterpart of those of the swamp- 

 dwelling, coastal Ki. paludos^im R.Br. Attention is drawn to 

 the similarity between the leaves of certain .species of the Order 

 ProteaceiB, and others of the Sapindacese (9; 1900, p. 586) by Mr. 

 H. Deane; and the writer has shown examples of variation 

 within a species in Lomatia silaifolia R.Br., (13; 1914, p.l59). 



