genus, and 2 species oi Ery thro pal uni Blume — an Indo Malayan 

 genus. All three are from the London clay of Ypresian age which 

 is, as nearly as intercontinental correlations can be made, the 

 same age as the Wilcox Eocene of southeastern North America. 

 In Engler's scheme the Olacaceae were placed along with the 

 Loranthaceae, Santalaceae, Myxodendraceae, Grubbiaceae and 

 Balanophoraceae in the order Santalales, between the Proteales 

 and Aristolochiales. In Hutchinson's more recent treatment 

 (1926) the order Olacales is proposed for the two families Olaca- 

 ceae and Opiliaceae and placed between the Celastrales and 

 Santalales and the phylogenetic relationships are, I believe, 

 accurately expressed as follows : 





Santalales 





T 



Rhamnales 



Olacales 



T 



T 



Celastrales 

 This corresponds much more closely with morphology and the 

 known as well as surmised geological history than Engler's 

 ideas do. The family Olacaceae, as now understood, contains 

 between 20 and 25 genera and less than 150 species of shrubs 

 and trees divided into 3 subfamilies all of which are represented 

 in the tropics of both the old and the new worlds. There are 6 

 monotypic genera — one each in Borneo, Mauritius and the 

 Amazon basin and 3 in Africa. There are 5 genera with about 

 23 species confined to America, 6 genera with about 16 species 

 confined to Asia and 4 genera with less than 10 species confined 

 to Africa. The genera Aptandra, Heisteria and Ptychopetalium 

 with about 30 species are confined to America and Africa. Scho- 

 epfia with about a score of species is confined to America and 

 Asia, Ximenia occurs in South America, Africa and Asia, Strom- 

 bosia ranges from Africa to Malaya, and Olax with about 30 

 species extends from Africa to northern Australia. So far as I 

 know this is the only genus that reaches Australia, and if true 

 would seem to indicate that the Olacaceae did not take part in 

 the Upper Cretaceous radiation of dicotyledonous floras. At the 

 same time the existing distribution of the family is as good 

 proof of its having had an extensive geological history as if the 

 actual records had been uncovered in the rocks. 

 Johns Hopkins University 

 Baltimore, Md. 



