PROCEEDINGS OF THE NATIONAL MUSEUM. 



opposite, thin apparently camptodrome secondaries; finer nervation 

 not preserved. 



Type.— Cat. No. 34,738. Counterpart 34,739, U.S.N.M. 



This specimen with its counterpart is all that has been observed in 

 the collections, and unfortunately it is not perfectly preserved. It 

 consists of a short stocky branch rather closely set with large leaf- 

 scars, and, judging from its similarity to the living species, indicates 

 the growth of four seasons. No very satisfactory measurements of 

 the leaves can be given. The petioles are about 1.5 cm. long, and the 

 leaves about 2 cm. broad, but the full size and shape of the latter can 

 not be ascertained. 



This species is thought to be most closely related to the livmg Pop- 

 ulus tremuloides Michaux, the well-known trembling aspen, being 

 especially like the short stunted branches and small leaves of trees or 

 bushes which have grown in very dry situations. The nervation of 

 this species is not quite typical for Populus tremuloides, and it is, of 

 course, possible that the characters above set forth may not indicate 

 this genus, but in any event, it seems distinct from described forms, 

 and may stand until more perfect material is obtamed. It has some 

 superficial resemblance to Panax andrewsii CockereU,* especially in 

 the clustering of the leaves and their size and probable nervation, but 

 the latter is interpreted as being a compomid leaf of five leaflets, and 

 moreover, the petioles are provided with prickles. 



POPULUS CRASSA (Lesquereux) Cockerell. 



Plate 18. 



Populus crassa (Lesquereux) Cockerell, Bull. Amer. Mus. Nat. Hist., vol. 



24, 1908. p. 83, pi. 8, fig. 22; pi. 10, fig. 42. 

 Macreightia crassa Lesquereux, Rept. U. S.Geol. Surv. Terr., vol. 8 (fret, and 



Tert. Fl.), 1883, p. 175, pi. 34, figs. 16, 17. 

 Diospyros cuspidata Kirchener. Trans. St. Louis Acad. Sci., vol. 8, 1898, p. 185. 



pi. 12, fig. 1. 



Type of Diospyros cuspidata. — Cat. No. 33,675, U.S.N.M. 



The type and only specimen of Earchner's Diospyros cuspidata is 

 absolutely identical with the figures of Macreightia crassa Lesquereux, 

 and it is probable that all were equally four-valved, notwithstanding 

 the appearance of the figures. That they have apparently been 

 correctly referred to Populus, is weU shown by the splendid specimen 

 figured (U.S.N.M., 50,332), which was contained in the paleobotani- 

 cal collections donated to the United States National Museum by 

 Mr. R. D. Lacoe. This is an absolutely complete drooping raceme 18 

 cm. long, with the rachis about 3 mm. thick, and showing about 

 thirty of the capsules attached by the short thick pedicels. The 

 point where the raceme was attached is broad, enlarged, circular 



lAmer. Nat., vol. 42, 1908, p. 581, fig. (ill text) 12. 



