MR* G. BENTHAM ON EUPIIORBIACE2R. 265 



genera, Ckrozophora and Mercurialis 6 species each, and Sperans- 

 hia 1 species. The two former, essentially European, appear to 

 have their chief seat in the eastern Mediterranean region, ex- 

 tending more or less southwards into the tropics ; Mercurialis is 

 there connected through the tropical African Micrococca with the 

 great Claoxylon group. Chrozophora and the isolated North- 

 Chinese Speranskia appear to me to be as distinct in character as 

 in geographical distribution from each other as from the American 

 Argithamnia, with which it has been proposed to unite them. 

 Their old association with Oroton may not have been so very far 

 wrong as is supposed, notwithstanding the difference in the sta- 

 mens which now removes them to a different subtribe. 



Five genera are extratropical in South Africa, and four of them, 

 comprising 9 species, exclusively so. Three, Leidesia. Adenocline y 

 and Seidelia, are, like Mercurialis, but in a different direction, 

 connected, through Micrococca, with the great Claoxylon group. 

 Toxicodendron is quite isolated and monotypic ; the fifth genus, 

 Cluytia, with 28 species, is systematically isolated, and geographi- 

 cally only spreads into tropical Africa ; but it has no near con- 

 nexions there, still less in any other country. 



Thirteen genera, comprising 32 species, are limited to tropical 

 Africa or only extend to Madagascar. Seven of them are mono- 



typic. 



Two genera, both monotypic, are limited to Ceylon. 



Fifteen genera, comprising 34 species, are as yet only known 

 from the Malayan archipelago or Malacca, or scarcely extend to 

 the South-Pacific islands. Nine of these are monotypic. 



Twenty-one genera, with about 140 species, are more or less 

 generally spread over tropical Asia including the Malayan archi- 

 pelago, a few of them extending to Australia, but none westward 

 into Africa. Only one of them is monotypic. 



Twelve genera, with above 320 species, are more or less gene- 

 rally spread over the whole tropical Africano-Australian region. 



None of them are monotypic. 



The Australian endemic genera of Euphorbiaceae (exclusive of 

 Euphorbiese and Stenolobea*) are five:— Ifooraper*, 2 species, allied 

 to Phyllanthus ; Petalostigma, 1 species, allied to the Indian 

 Putranjiva ; Ccelebogyne, 1 species, allied to Alchornea ; Dissilia- 

 ria, 3 species, allied to the Malayan Choriophyllum ; and Adriania, 

 5 species, perhaps distantly connected with Croton. 



There are nine New-Caledonian endemic genera, comprising 20 



