1895. | NEW YORK ACADEMY OF* SCIENCES. 269 
tomous [at short intervals], then more irregularly branching 
[in a dichotomous manner]. There are about 10 hydrothecz in 
the space of a centimetre, and the branches [of the hydrosome ] 
are about one-half of a millimetre wide [or more]. The cells of 
the hydrosome are directed forward [and upward], and each 
terminates in a mucronate point. The primary branches do not 
appear to be celluliferous, but cell-bearing branches shoot out 
from the primary.* 
Size. Width of the hydrosome 15 to 20 millimetres; height, 
about 10 millimetres. 
Horizon and locality. Black shales of Div. 3b of the St. John 
group at Navy Island, St. John Harbor. Found last summer 
also in the shales of Div. 3c in occasional layers, over which the 
hydrosomes of this species are freely scattered. 
There is a considerable variation in the attitude of the 
branches of this species. The figures in Trans. Roy. Soe. Can. 
are of the spreading variety from Div. 3b. The one here given 
is the average form of those in Div. 3c, though some with even 
more erect branches are to be found. 
Dr. J.C. Moberg figures a species from Hunneberg in Sweden 
(B. (2?) Hunnebergensis), whose branches have the attitude of 
those of B. patens, but it is a much smaller species and less fre- 
quently branched. 
A species from the Shineton shales, B. Callavei, described by 
Prof. Lapworth, bears a close resemblance to this species in the 
attitude of its branches, but the figure given represents it as 
bifureating regularly, and presumably in one plane, as there are 
but two main branches; thus it has not the shrubby growth of 
Bb. patens, but in its simple branching resembles B (?) Hunne- 
bergensis of J.C. Moberg. B. Callavei does not agree with our 
species in the spacing of the thece on the hydrosome; it has 
74 cells to the centimetre, while B. patens has about 10 cells. It 
would appear from this that there is no described species to 
which B. patens can be referred. 
BryOGRAPTUS sPINosus, Matt. Pl. XLVIIL., figs. 3 a and 6. 
Clonograptus spinosus. Trans. Roy. Soe. Can., vol. x., see. iv. 
p- 97, pl. figs. 3 a and b. 
A slender species with distant hydrothece set very obliquely 
to the axis, and having a spine at the outer end of each hydro- 
theca. The branches of the hydrosome are about three-quarters 
of a millimetre wide, and there are about 8 hydrothece in the 
space of 10 millimetres. 
*The bracketed parts of this paragraph are not in the original description of the 
species. 
