138 CANADIAN FOSSILS. 
DICTYONEMA QUADRANGULARIS, Hall. (n.s.) 
Plate XX, figure 5. 
Description.—Frond large, robust. Branches lmear, nearly parallel, 
rarely bifurcating: branches about five hundredths of an inch in width, the 
interspaces having an average width of eight hundredths of an mch. Fen- 
estrules quadrangular, length and breadth usually nearly equal: con- 
necting filaments nearly as wide as the branches, expanded at their 
junction with the latter, so as to give an apparent sub-hexagonal form to 
the fenestrule. Cellules not determined. Surface free from any charac- 
teristic markings. 
This species is very distinct from the two preceding, and from nearly all 
other species, by the almost parallel direction of the branches. A fragment 
an inch and a quarter wide by three inches long, shows not more 
than four or five bifurcations. The apparently hexagonal form of the 
fenestrules may be due m part, or entirely, to the breaking or wearing away 
of the margins of the stipes, or of the connecting filaments, or of both. 
The short equilateral fenestrules form the most promiment and charac- 
teristic feature. It occurs with the other species just described, and with 
Graptolithus rigidus, in the same hard shales. 
EXPLANATION OF Figure or DICTYONEMA QUADRANGULARIS, Hall. 
PLATE XX. 
5. <A fragment of a frond, of natural size. 
‘ 
Formation and Locality Quebec group; Point Lévis. 
DictyonEMA Murravi, Hall. (a. 8.) 
Plate XX, figures 6, T. 
Description.—Frond very large, gradually spreading from its origin. 
Branches strong, width from five to eight hundredths of an inch, infre- 
quently bifurcating; divisions little diverging, the interspaces being little 
wider than the branches. The fenestrules have a width of eight by a length 
of eleven hundredths of an inch. The connecting filaments are wide at 
