148 BOTANICAL GAZETTE [SEPTEMBER 
period. The data for this table are derived from Schimper,’ 
Lesquereux,3 and Durand.‘ 
Cretaceous 
Triassic | Jurassic |~~—-————_|_ Eocene | Miocene | Present 
Lesquereux Schimper 
DOCAT PR. 4 <) ce are 30. 12,5 26.6 20:3 16.1 1.0 
Coronaries 2.2 v... 100.0 38.4 25.0 4.3 19.4 14.0 
Nadiflorses 4: 2: 35..% 12.5 23.3 14.1 7.0 5.5 
Calyeinit. 2055.5 vO) 12.5 26.6 22.8 21.8 67 
CUIAROSS 5.0%, c os 15.3 12.5 25.0 28.3 B1.0 
Eiydrales.n cea we ss 0.0 0.0 ea 1.6 f°) 
Epigyndé........+. 25.0 6.6 3.3 5.6 14.0 
Microsperme ...... 0.0 0.0 0.0 25.7 
The history of the dicotyledons, as far as yet made out, is 
relatively simple. In the Cretaceous we find that from go to 95 
per cent. of the known species may be referred to the two primi- 
tive groups (orders) Thalamiflore and Calyciflore. Taking 
Schimper’s results, we find that nearly 60 per cent. are referable 
to the Thalamiflore, representing nearly equally the groups 
(sub-orders) Ranales, Caryophyllales, and Malvales. The less 
important groups, Parietales, Polygalales, Geraniales, and Gutti- 
ferales, have not yet appeared; at least no representatives have 
been certainly recognized. 
The Calyciflore are represented by species of Rosales, — 
Myrtales, Celastrales, Sapindales, and Umbellales. Here the 
numbers are quite unequal, ranging from about 10 per cent. for 
Myrtales and Umbellales, to 13 per cent. for Rosales, 26 per 
cent. for Celastrales, and 40 per cent. for Sapindales. The 
Heteromere and Bicarpellate were scarcely represented, 
Schimper recording but a single species each of Ericales, Eben- 
ales, and Gentianales. If we make use of the data brought 
together by Lesquereux,} we find little change in the general 
results. There is here a slight preponderance of Calyciflore 
2 Traité de Palzontologie Paige 1869-1874. 
3 The Flora of the Dakota Group. 1891 
4Index Generum Phanerogamarum. 1888. 
5 The Flora of the oaks Group. 1891. 
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