42 THE RARITAN FLORA. 



V. GEOGRAPHICAL DISTRIBUTION. 



OCCURRENCE IN NEW JERSEY. 



Identifiable remains of leaves are by no means uniformly dis- 

 tributed in the Raritan formation, even in the argillaceous beds. 

 On the contrary, good material is extremely local. Traces of 

 former vegetation are much more abundant, as shown by the 

 black clays, with "hacksel," as the Germans term comminuted 

 vegetable material, and by beds of lignite which are sometimes 

 several feet in thickness. Usually, however, where leaf remains 

 occur in these black clays or in the presence of much lignite, they 

 are so impregnated with ulmic or carbonaceous matter that they 

 are very perishable. This is especially true of material collected 

 around Sayreville and applies with equal force to numerous other 

 leaf-bearing outcrops. The bulk of Prof. Newberry's material 

 came from one pit in the Woodbridge district (Cutter pit), and 

 the writer's best material comes from a single pit at South 

 Amboy (Allen and Clark pit). 



There are 24 species for which there are no exact data as to 

 locality or horizon. These include a number of species which 

 occur elsewhere in older or younger strata and whose position 

 in the Raritan w^ould be a matter of considerable interest. Among 

 them may be mentioned: 



Celastrophyllum Brittonianum Hollick. 



Celastrophyllum cretaceum Lesq. 



Dehvalqiica groenlandica Heer. 



Hymenoea dakotana Lesq. 



Sequoia concinna Heer. 



Thiiyites meriani Heer. 



What appears to be one of the lowest leaf-bearing horizons in 



the Raritan is that near its western border, at Milltown, from 



which the following species have been collected by Charles H. 



Mead of that place and by Ward and White of the U. S. Geo- 



