Maryland Geological Survey 477 



Celastrophyllum latifolium Fontaine 

 Plate XC, Figs. 6-9 



Celastrophyllum latifolium Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 

 1889, p. 306, pi. clxxii, figs. 3, 6; pi. clxxiii, fig. 13. 



Celastrophyllum tenuinerve Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 

 1889, p. 306, pi. clxxii, fig. 2. 



Celastrophyllum obovatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 

 1889, p. 307, pi. clxxii, figs. 9, 10. 



Celastrophyllum latifolium Fontaine, 1906, in Ward, Mon. U. S. Greol. Sur- 

 vey, vol. xlviii, 1905, p. 559, pi. cxvi, fig. 6. 



Protewphyllum Uhleri Fontaine, 1906, in Ward, 1905, Mon. U. S. Geol. Sur- 

 vey, vol. xlviii, 1905, p. 564, pi. cxviii, fig. 5. 



Celastrophyllum oiovatum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., 

 vol. xlviii, 1905, pp. 550, 560, pi. cxv, fig. 6; pi. cxvii, figs. 2, 3. 



Description. — Leaves of delicate texture, obovate to nearly orbicular 

 in outline, with a broadly rounded tip and a somewhat decurrent base, 

 length 3 cm. to 6 cm., greatest width 2.2 cm. to 4.5 cm., widest about 

 half way between the base and apex, margin entire. Midrib and secondary 

 venation delicate. Secondaries numerous, approximately parallel, 

 branching from the midrib at a usually acute angle, the lower pairs long 

 and curved upward parallel with the leaf margins, camptodrome. There 

 is considerable minor variation in the venation characters of these leaves 

 and as the delicate secondaries tend to be obliterated in all except the basal 

 part of the leaves where they are more ascending, specimens in this state 

 of preservation appear to have a palmate venation. 



This species, which is rather common in the collections from Federal 

 Hill, shows considerable variation in size and appearance and is the 

 least satisfactorily determined CelastropJiyllum from the Potomac Group 

 suggesting the genus Chondrophyllum rather than G&ldstrophyll'wm. 

 This variation is really one of the distinguishing characters of the species 

 as here defined. A single specimen has been collected from the Yinegar 

 Hill locality. A single specimen from Federal Hill, slightly shorter and 

 wider than the average with consequently more obtusely branching 

 secondaries, was made the basis for the species ProtecBpliyllum Uhleri 

 Fontaine, although it is not allied with that genus and is clearly a slight 

 variant of the present species. 



