On a Species of Goniograptus. 427 
The fourth and last arm is broken, and exhibits only six 
celluliferous stipes on one side, and five on the other, 
The whole polypary, about seven inches across, thus con- 
sists of sixty-seven celluliferous stipes, as preserved, which 
number would no doubt have been increased to about 
eighty, had the polypary been perfect. This number is 
greatly in excess of that obtained in the Australian 
specimens, just double. 
The thece are acutely pointed and triangular, and 
number from 30 to 32 inthe space ef one inch. They are 
inclined at an angle of from 30° to 50° to the axis of the 
stipe, this variation being probably due to the mode of 
preservation of the specimen. Only here and there is there 
a short row of thec visible in this fine specimen, the 
branches having been crushed in a direction opposite to and 
so as to hide the cell apertures and thece. 
‘As in Prof. McCoy’s species, the Canadian example 
“forms a slightly quadrate circle or rounded square” with a 
diameter of nearly seven inches (about cight inches when 
perfect). 
The presence of a disc or membrane clasping the sicula, 
funicle, &c., also extending upwards and outwards along 
the arms has already been noted, which feature was not 
preserved in the Australian specimens, which absence is 
evidently due to the mode of preservation and fossilization 
‘ather than to the mode of growth of the polypary. 
Of the disce-bearing graptolites known to the writer, we 
have the following:—Loganograptus Logani, Hall; L. 
Kjrulfi, Brégger; Dichograptus octobrachiatus, Hall; Tetra- 
grapius Headi, Wall; T. alatus, Hall; 7’. crucifer, Hall ; and 
Climacograptus bicornis, Hall. This dise which acted both 
as support and float in the genus Goniograptus, as well as 
in the other species just enumerated, would act also as a 
more or less rigid membrane in keeping the celluliferous 
stipes from entangling—causing them to lie more cr less 
evenly in one place, On Climacograptus bicornis, this use of 
the dise is not so evident. 
When compared together, the Australian and American 
