FOSSIL ANGIOSPERMS 275 



TERTIARY FAMILIES. To the five monocotyledoncms fami- 

 lies represented during the Cretaceous the Tertiary adds at least 

 fourteen, the older families also showing a largely increased 

 development. It will be interesting to note how these addi- 

 tional families fill out the ten great series of Monocotyledons. 

 In each case the Cretaceous representative is put in paren- 

 thesis. 



1. Pandanales. (Pandanaceae), Typhaceae, Spargania- 

 ceae. This primitive series is thus completed as at present 

 recognized. 



-2. II el ob idles. (Potamogetonaceae), Juncaginaceae, Buto- 

 maceae, Hydrocharitaceae. This series is completed by the 

 appearance of its highest member, and the Butomaceae are 

 fairly representative of the Alismaceae. 



3. Glumales. Gramineae, Cyperaceae. The occurrence of 

 irra -like forms during the Jurassic has been referred to, but 

 the absence of grasses from the Cretaceous record seriously 

 militates against the claim that these Jurassic forms were 

 grasses. It is since the Tertiary that the Gramineae have be- 

 come most richly developed and widely spread, numerous ex- 

 tinct genera having been described. Although it would seem 

 impossible to determine the relationships of grasses from frag- 

 mentary material, and doubt must be expressed as to the rela- 

 tionships implied in such names as Poacites, Arundinites, etc., 

 there is good evidence for the statement that the earliest grass 

 types were related to such tropical forms as Arundo, Phrag- 

 mites, Bambusa, etc. 



-i. Pal males. (Palmaceae). The only family of the series 

 became much more largely developed and wide-spread during 

 the Tertiary. 



5. Synanthales. Cyclanthaceae. This family, the only 

 member of the series, appeared during the Eocene Tertiary, 

 and its early association with the screw-pines and palms con- 

 firms its supposed relationship to them. 



6. Amies. (Araceae?). The doubtful appearance of this 

 family during the Cretaceous has been mentioned, and this 

 claim is not helped by the fact that they are no better known 

 during the Tertiary. Such forms as do occur resemble Acorns 

 and Pistia. The so-called " Protolemnas " seem too doubtful 

 to be included. 



