744 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



present I am unable to suggest a closer affinity. They have the same size, 

 shape, and approximately the same nervation as G. platanifolia Ward, 1 from 

 the Fort Union group, differing, however, in not having a toothed margin. 

 Professor Ward writes that the specimen upon which his species was 

 founded is quite obscure, and it is possible that they may really be nearer 

 alike than appears from the drawings. Additional material is needed to 

 fix their status. 



I have ventured to call this a new species, and have named it in honor 

 of Mr. E. C. Alderson, who accompanied the expedition on which it was 

 obtained and assisted in making the collections. 



Habitat: Specimen Ridge, opposite mouth of Slough Creek and near 

 head of Crystal Creek; collected by Ward and Knowlton, August, 1887. 



ARALIACEJ1. 



Aralia wrightii n. sp. 

 PL 01, fig. 1. 



Leaf firm, coriaceous, narrow in general outline, pahnately 3 (possi 

 bly 5) lobed; central lobe largest, long, ovate-lanceolate, slender-pointed; 

 lateral lobes slender-lanceolate, half the length of the central lobe; all 

 margins perfectly entire; basal portion of leaf unknown ; primary nervation 

 palmate; middle lobe with a pair of opposite nerves nearly at right angles 

 to the midrib, which pass to the sinus, those above with about 10 pairs of 

 alternate camptodrome secondaries, which are much curved upward and 

 arched along near the margin; intermediate secondaries occasional; lateral 

 lobes with a strong midrib and about 8 pairs of alternate or subopposite 

 much-arched camptodrome secondaries; finer nervation consisting of very 

 fine quadrangular areolation. 



This very peculiar species is unfortunately represented by only the 

 fragmentary leaf figured. The basal portion is entirely destroyed and 

 it is therefore impossible to determine whether there were 5 or only 3 

 lobes. There is some evidence in favor of its having been 5-lobed. The 

 sinuses separating the lobes are somewhat rounded. The central lobe is 

 very much the larger. From the sinus it has 6 cm. preserved and must 

 have been 8 cm. or more in length when entire. In the broadest part, 



' Types of the Laramie PI., p. 89, PI. XL, fig. 1. 



