66 T. D. A. Cocker ell — Descriptions of Tertiary Plants. 



normal, and frequently the only one present ; so it may per- 

 haps be an open question whether the appearance of rugelii 

 leaves on true saceharum is due to reversion or to hybridiza- 

 tion. In the position of the lobes, the fossil resembles A. 

 pennsylvanicum L. 



Hob. — Florissant, in the Miocene shales. Station 14 (3. A. 

 fiohwer, 1907). Peabody Museum, Yale, Cat. No. 1002. 



Acer florigerum, sp. nov. Figure lc. 



Flower ; pistillate, apetalous, tetramerous. Styles two, sepa- 

 rate to the base, long, exserted, straight or very slightly curved, 





Figl 1. (a) Limnobium obliteratum ; (b) Acer perditum ; (c) Acer florigerum, 

 x 2 ; {d) Phaca wilmattce. 



about 4 mm long. No sign of any stamens. Sepals four, lan- 

 ceolate, pointed, only about the basal two-fifths united. 



In the form of the styles, this resembles A. nigrum Mx., 

 but the calyx segments are nearly as in A. drummondii in 

 form. Only four calyx segments or sepals are preserved, and 

 there were apparently no more. The dioecious tetramerous 

 flowers indicate affinity with such species as A. tetramerum 

 Pax, A. hetidifolium Maxim., and A. harbinerve Maxim. 



Hob. — Florissant ; Miocene shales ( W. P. Cockerell, 1907). 

 It was found at Station 14. I think this flower may safely be 



