NORTH AMERICAN GRAPTOLITES Wil 
Thecz cylindrical, at first directed perpendicularly outward from virgula, 
then deflected through nearly 90° so as to become directed proximally 
(“distally”) and almost parallel with virgula, and at the same time to make a 
small angle with the plane of the shale-section (rising up from or sinking 
down into the rock); pretty uniformly 24 to 26 in 25™"; apparently without 
any overlap. 
Horizon and locality.—Upper Dicellograpsus zone, Magog, Canada. 
Easily recognized, in connection with the dimensions, by the superficial 
outline which shows a series of rather squarish thecal outlines distinctly alter- 
nating on the two sides. 
Climacograptus phyllophorus Gurley, sp. nov. Plate IV., Figs. 4-6. 
(Cliimacograptus parvus Hall, 1865, Can. Org. Rem., Dec.2, p. 57; 
nomen nudum.) 
Polypary gradually widening from distal (‘‘ proximal’’) extremity, attaining 
its full width in the length of 6 to 8 thece; ventral margins above this point 
parallel. Length, exclusive of proximally (“distally”) prolonged virgula, 10 
to 30™™ (usually about 20™); maximum width, 1™.5 to 2™™; distal 
(“proximal”) extremity narrow and abrupt, with two short lateral spines; and 
an extension of virgula for 2 to6™". Proximal (“distal”) extremity abrupt, 
showing a prolongation of the virgula which terminates in a “disk,” varying 
in shape (apparently with age) from narrowly lanceolate to broadly elliptic, 
6 to ro™™ long, and 1 to 3™" broad. Thece 30 to 36 in 25™", short, perpen- 
dicular, apertural margins concave, the excavation nearly horizontal (slightly 
inclined distalward), occupying nearly one-third of width of the polypary. 
Horizon and locality—Lower Dicellograpsus zone (of which it is one of 
the most characteristic species), Stockport, N. Y. 
This species was identified by a comparison with Hall’s types in the 
American Museum of Natural History in New York City. It is very distinct 
from C. dzcornzs and C. tyficalis, differing from the former in the absence of 
the three prominent spines and the disk developed around them, and from 
the latter by the constantly prolonged virgula.* It is also much smaller than 
either dzcornzs or typicalts. The species which it most closely resembles is 
C. scalaris (L. =normatlis Lapworth), and for this form it has been mistaken 
(as it easily might be, and formerly was by me) by Ami. 
The chief interest in the species lies in the “disk.” This has the form of 
and strikingly resembles an elliptic pinnate-veined leaflet, a resemblance 
heightened by the likeness of the virgula to the midrib, and the presence of 
several obscure, obliquely directed fibers running from it on either side out- 
*If, as would naturally be expected, C. “ygzcalis has a proximally (“distally ”( 
extended virgula, it never (within my experience) shows it on the shale, and for prac- 
tical diagnosis this absence is all-sufficient. 
