DESCRIPTIONS OF SPECIES. 133 



Formation and locality: Cretaceous (Dakota group). Fort Harker, 

 Kansas. 



Protophyllum Sternbergii Lesq. 



PI. X; XL 



Cret. Fl. (1874), p. 101, PI. XVI ; XVIII, fig. 2. 



Pterospermites Sternbergii Lesq. Hayden's Ann. Rept. 1872 [1873], p. 425. 



The specimens figured on Pis. X and XI represent but parts of some 

 of these magnificent angiospermous leaves found in the Dakota group of 

 Kansas. They apparently represent Lesquereux's P. Sternbergii, but are 

 perhaps not distinct from those described by him first as Credneria 

 Lecontiana, and subsequently Protophyllum Lecontianum. 



The leaf figured on PI. X seems to have been nearly round and at 

 least 12 inches in diameter; that represented on PI. XI was more ovate 

 and was still larger. Both were included in the collections made at Fort 

 Harker by Mr. Charles H. Sternberg, and Lesquereux has done only 

 justice to him by attaching his name to the finest species contained in the 

 large collection of fossil plants which he made there. 



As previously remarked, no satisfactory relationship has been estab- 

 lished between Protophyllum and living genera of plants, but I would 

 suggest that some of the species of Cocoloba, such as C. pubescens, present 

 many points of similarity of structure. 



Formation and locality: Cretaceous (Dakota group). Fort Harker, 

 Kansas. 



Pterospermites dentatus Heer. 



PI. LIII, figs. 1, 2; LIV, fig. 4. 

 Fl. Foss. Arct., Vol. I (1868), p. 138, PI. XXI, fig. 15b; XXIII, figs. 6, 7. 



The leaves here represented are probably not distinct from those 

 described by Professor Heer under the above name, although the fragment 

 which he had did not permit him to give a full characterization or satisfac- 

 tory figures. His description consists of three words: "Foliis, sub-peltatis, 

 dentatis," all of which is true of the much more complete specimens before 

 us, but they also show that the base of the leaf is entire, or nearly so, the 

 upper margin variably dentate or nearly entire. These specimens also 

 show that the leaves of P. dentatus — if we acccept that name for the 



