498 



Antarctic Origin of the Tribe Schwnece. [Mar. 12, 



(4.) Each of these two cosmopolitan species, superabundant in in- 

 dividuals, has thrown off a local offshoot, which in A.D. 1902 

 produces in our minds the impression of a geographic sub- 

 species. 



The whole preceding argument hangs on the question whether I 

 hare included the right genera in my sub-order Schcenese. The 

 Schoenese dealt with in this map, are the 3-style-branched Schcenese of 

 Bentham, which are regarded as a very closely allied group by Kunth, 

 Boeckeler, F. Mueller, and the orthodox cyperologists. In the Plant- 

 families of Engler and Prantl a different system has been adopted ; 

 this, however, has not been accepted in their writings on Cyperacese 

 either by Germans as Goebel, Solms-Laubach, Celakovski, or by 

 Americans as Britton, Bailey. The present map is grounded on the 

 systematic arrangement of Cyperacese by Bentham. 



The few points in the map which I regard myself as doubtful I 

 have given against my own case, e.g. : — 



The outlying species marked in the North-west Himalaya is a 

 small species — an elementary form — which I have placed in the 

 Schcenese, but may possibly really belong to some other sub-order. 



Several outlying localities in West Africa and the West Indies, 

 belong to one genus — Bemirea — which was regarded by Bentham as an 

 abnormal member of the Schcenese. 



There are several, and some large, orders of plants, as Proteacese, 

 Restiaceae, &c, confined, or nearly so, to the Southern Hemisphere : 

 the present case is only one branch of a very large argument, pre- 

 sented in detail. 



EXPLANATION OF MAP (PLATE 14). 



The map represents the world-distribution of the 266 species which constitute 

 the Schcenese, with reference to the 23 sub-areas lined out in black. For each 

 species a mark is put in each sub-area in which it occurs. 



For 262 species the mark is a black dot. 



For the two species Schoenus nigricans. Linn., Schoenus ferrugineus, Linn., the 

 mark is a ring. 



For the two species Cladium Jamaicense, Crantz, Claclium triglonieratum, ~Nees, 

 the mark is a cross. 



