132 CANADIAN FOSSILS. 
DENDROGRAPTUS ? (CALLOGRAPTUS ?) DIFFUSUS, Hall. (n.s.) 
Plate XVIII, figures 1-3. 
Description.—Stipe strong, rigid, gradually decreasing in width at each 
bifurcation : bifurcations numerous, irregular, the stipe slightly bending at 
each division, and the branches and branchiets strongly diverging. Sub- 
stance of the fossil extremely compressed, obscurely corrugated ; cellulifer- 
ous face flattened. Cellules apparently arranged ina single series along the 
longitudinal centre of the branches in the form of minute indentations, 
and leaving similar minute pustuliform marks in the impressions of the 
branches ; cellules about thirty-six in the space of an inch. 
This species differs from D. erectus in the more rigid and more widely 
diverging branches. It occurs in a dark colored or nearly black shale, 
associated with Graptolithus extenuatus, Climacograptus antennarius, 
Retiograptus tentaculatus and Retiolites ensiformis. 
EXPLANATIONS OF Figures oF DENDROGRAPTUS? (CALLOGRAPTUS ?) DIFFUSUS, Hall. 
Puate XVIII. 
1. A portion ofa broken frond from near the base. The test is removed in some 
parts, showing celluliferous markings. 
2. A fragment of another specimen with similar cell-markings. 
3. An enlargement, showing the cell-apertures. The specimens are extremely 
compressed. 
Formation and Locality— Quebec group ; Point Lévis. 
DENDROGRAPTUS GRACILIS, Hall. (n. s.) 
Plate XVIII, figures 5, 6. 
Description.—Frond diffuse, numerously branched. Branches very 
slender, extremely elongate and sub-pendulous, celluliferous on one side ; : 
the cells are arranged in an apparently sub-alternate order, or have assumed 
this order during the compression of the specimen. Surface striated: cel- 
lules deeply indenting the margin of the branchlet, and the outer margin 
furnished with a mucronate extension. 
