NORTE VANE RICAN GRAPTOLITAES= 
Il. “VERTICAL RANGE. 
WitHour attempting to discuss at length the general 
aspects of this subject, attention may be directed to the 
following points: 
1. The vertical range of the American species presents a 
complete parallel to the range in other countries. This parallel 
is not a general one only, but is exceedingly detailed, extending 
beyond the genera down to the species, which in each horizon 
correspond to those of the equivalent European horizon almost 
without exception, although of course not every European spe- 
cies occurs in America, or vice versa. Still the number of spe- 
cies common to the two sides of the Atlantic is surprising, and 
it will doubtless be increased by future research. 
2. This detailed correspondence furnishes good ground for 
the expectation that eventually the American strata, like the 
European, will be mapped out, zone above zone, and for the 
hope that here, too, the graptolites may ultimately become one 
of the mainstays of stratigraphy. Much has of course yet to be 
done, but the peculiar associations of species in several collec- 
tions so nearly parallel those which abroad characterize particu- 
lar zones, that it is difficult to believe that here they have a dif- 
ferent significance. 
3. The extent of the range of the group as a whole, is 
unprecedented, as it extends from the Cambrian to and into 
the Carboniferous. 
4. A striking peculiarity of the American fauna is the almost 
entire absence of the great European family of the Wonograptide 
*Continued from THE JOURNAL OF GEOLOGY, Vol. IV., No. 1, January-February, 
1896, p. 102. 
291 
