C. H. Hitchcock— Helderberg Rocks in New Hampshire. 557 
their Eocene floras, and nothing whatever of their Pliocene, 
all those theories on the ‘‘march and countermarch” of th 
floras according to the upheaval of chains of mountains are 
merely imaginary. 
Columbus, Ohio, April 14th, 1874. 
Arr. LIL—On Helderberg Rocks in New Hampshire; by 
C. H. Hircucock. 
[Concluded from page 476.] 
Littleton area of Helderberg. 
they then dip northwesterly ; and finally several measure 
3 ° B., 80°, S. 10° E., and 
5°, S. : 
slate, chiefly siliceous. Next we pass up a hill, over the Lisbon 
* The courses of all the sections are indicated upon the map, page 471. 
