GRAPTOLITES. 133 
This species is well marked by its extremely slender branches, which 
are distinctly serrated, while one side is strongly striated, and the deep 
indentations give a semi-articulate character to the branches. 
Several fragments of this species have been found associated with 
Callograptus elegans and C. Salteri, but none more nearly entire than the 
specimen figured. 
EXPLANATIONS OF Figures oF DENDROGRAPTUS GRACILIS, Hall. 
Prats XVIII. 
5. Two of the larger branches with their sub-divisions, of the natural size. 
6. An enlargement from one of the branchlets, showing the striate surface and 
the deep indentation of the cellules. 
Formation and Locality.—Shales of the Quebec group; Point Lévis. 
Genus CALLOGRAPTUS, Hall. (m. g.) 
Gr. Kaddos, pulcher, and ypapw, scribo. 
Generic characters.—Flabellate fronds, with numerous slender bifur- 
cating branches proceeding from a strong stem or axis. Branches and 
divisions celluliferous on one side, the opposite side striate ; sometimes dis- 
tantly and irregularly united by transverse dissepiments. The non- 
celluliferous side sometimes presents a semi-reticulate appearance. 
The aspect of these fronds is intermediate between Dictyonema and 
some forms of Dendrograptus ; but they have not the regular reticulate 
structure of the former, while the sub-divisions of the branches are quite 
similar to some of the species of that genus. In the mode of branching 
and the form of cell-apertures, the present genus is quite different from 
the typical species of Dendrograptus. 
The slender branches and minute points which indicate the cell-apertures 
render it impossible, with the specimens in my possession, to determine 
satisfactorily the characters of the latter: they appear as simple oval 
impressions upon the surface of the compressed branches. 
It is possible that some of the species of this genus may have grown in 
funnel-shaped fronds, as Dictyonema. 
