( 633 ) 
tangents. If we add the second tangent in the corresponding node to 
each of these tangents, these new set of z tangents intersects the 
right line / in z points P'. The coincidences of the correspondence 
(P,P') are of two kinds. They may originate in the first place 
from cuspidal tangents, in the second place from the points of inter- 
section of / with the curve H; each of these latter points of inter- 
section however is to be regarded as a double coincidence. Thus 
22 = 12 (n—1) (n—2) + 6 (n—1) = 6 (n—1) (2n—32). 
The curve of ZEUTHEN is of class 3(n—1)(2n 
3). 
ER RAT AY 
Page 504, line 13, for members read member. 
, 004, ,, 15, ,, not wanting read wanting. 
» 009, ,, 24, ,, blewish read bluish. 
(April 19, 1905). 
