140 CANADIAN FOSSILS. 
PTILOGRAPTUS PLUMOsUS, Hall. (n. s.) 
Plate XXI, figures 1-4. 
Description.—F ond bi-pimnate, branching. Branches slender, plumose ; 
the axis round and smooth on the non-celluliferous side, and grooved on the 
opposite side. Pinnules simple or rarely divided, alternate, long and 
slender, flexuose, rising at an angle of 40° to the axis. Cellules minute, 
arranged upon one face of the pinnules. 
The entire form of this species is unknown : the branches appear to have 
been rounded, solid, and very gradually tapering. The pinnule are slender, 
linear, maintaining their width to the obtuse extremities: they have 
sometimes a length of about five eighths of an inch. Near the base they 
are solid ; beyond this they are flattened and slightly rugose (as if from 
contraction), and preserve very little substance. _ It has not yet been satis- 
factorily determmed whether the cellules are arranged in a single linear 
series on one side of the pinnule, or in a double alternating series. 
EXPLANATIONS OF Figures or PTILOGRAPTUS PLUMOSUS, Hall. 
PiatTe XXI. 
A fragment which is three times branched. 
A slender simple branch. 
An enlargement from the specimen fig. 1. 
A further enlargement of a portion of the same; some of the branches showing 
markings like cell-apertures. 
moo bo et 
Formation and Locality—Shales of the Quebec group; Point Lévis. 
PTILOGRAPTUS GEINITZIANUS, Hall. (n. s.) 
Plate X XI, figures 5-8. 
Description.—Frond numerously and irregularly branched. Branches 
thick and strong, irregularly bifurcating. Pinnule broad and strong, 
closely alternating on opposite sides of the branches. Cellules large, 
arranged on one face of the pmnule: non-celluliferous side smooth, or 
corrugated from compression. 
This species differs from the preceding in its stronger and coarser habit, 
its more frequent and irregular branching, in the broad flattened branches 
and the broader pinnulze, of which there are about six in the space occupied 
by nine in the other species. The cellules are stronger, and apparently 
more distant. 
