GRAPTOLITES. 85 
and slightly curved forward: cell-partitions usually well marked, and 
near the base, making a much less angle with the axis than towards the 
aperture. 
When the funicle is broken, this species sometimes occurs like the bi- 
brachiate forms, as in fig. 5 of plate iv, and in that condition bears some 
resemblance to G. nitidus ; but its stipes are wider, its habit more robust, 
the cellules more curved, making a greater angle with the axis; the den- 
ticles coarser and more equilateral, and usually mucronate or sub-mucro- 
nate. No pustules at the base of the cell-partitions, as in G. nitedus, 
have been observed in this species. There is also a resemblance between 
G. patulus and this species ; but in that one the stipes are usually more 
slender, the denticles more mucronate, the curve of the aperture much 
greater, and the cells make a much greater angle with the axis. 
This species is associated in the same shales with Gt. nitidus, G. exten- 
sus, G. constrictus, and Phyllograptus tlicifolius. I have united with 
this species the specimen represented in figs. 9 and 10, of plate iv, though 
it presents variations in some of itscharacters. A small portion of one of the 
stipes near the base of this shows a number of cellules or serratures equal 
to twenty-six in the space of an inch. Its affinities are more nearly with 
G. bryonoides than with any other; and having but this individual, I refer 
it for the present to that species. 
EXPLANATIONS OF FIGURES OF GRAPTOLITHUS BRYONOIDES, Hall. 
Pirate IV. 
1, 2, 3. Young individuals of this species. 
4, An older individual. 
5. A young specimen preserving two of the stipes, the funicle having been broken. 
6. An enlargement from fig. 1, showing the radicle, funicle, and origin of the four 
stipes, with a few of the earlier cellules. 
7. An older and larger specimen. 
8 An enlargement showing the character and proportions of the cellules. 
9. A small individual, preserving the four stipes in part, which are somewhat more 
slender than the usual forms of this species. 
10. An enlargement of the base of the specimen, showing the cell-denticles on one 
of the stipes, and a proportionally longer funicle than in fig. 8. 
11. An extremely elongated stipe, the lower end showing the commencement of 
growth; the distal extremity is broken. 
Puate III. 
11. A fragment of a stipe from the rough shales, with Phyllograptus ilicifolius. In the 
character of the cell-denticles it resembles the specimen pl. iv, fig. 9, and 
with that one may constitute a distinct species. 
12, An enlargement of a part of the specimen fig. 11. 
F 
