270 ; TRANSACTIONS OF THE [May 20, 
This species is easily distinguished from Dictyonema flabelli- 
forme, with which it is found, by its larger and more distant 
hydrothecz [also by the thinner substance of its hydrosome ]. 
This species, of which only fragments were had at first, was 
doubtfully referred to Clonograptus; the better material now 
had shows that it cannot be thus placed, as the mode of branch- 
ing is that of Bryograptus. The branches are ascending, clus- 
tered, and extend to the sixth degree of oS 
Size. Length of the hy drosome 35 + mm.; width, 30 + mm. 
Horizon and locality. First described trom Div. 3b, now also 
found in Div. 3c at Navy Island. 
This species is nearly related to B. Kjerulfi of the Norwegian 
Cambrian rocks, and has about the same number of thecz on a 
similar space of the hydrosome. B. Ajerulfi has T-9 according 
to Lapworth, but Brogger’s figure gives 10 cells in a distance of 
10 mm. Lapworth’s figure shows a branching to the third de- 
gree, Brogger’s to the fourth, but the branching in B. spinosus 
extends to the sixth and seventh degrees; it is much more 
bushy. 
BryoGRAPTuUs LENTUS n. sp. Pl. XLVIII. Figs. 2 a and b. 
The initial part of the hydrosome is wanting. Branches as- 
cending, slender, crowded, flexuous; angle of furcation narrow 
(30° to 40°), except at the final angle where it is about 40° to 
50°. Hydrothecz numerous, continuous on all the branches 
known, free for most of their length, somewhat spinous-pointed, 
about 7 or 8 in the space of ten millimetres. Extreme width of 
the branches about 1 mm. 
The width of the branches of this species is greater than that 
of the other Rhabdopores that occur with it, but the thickness 
of its branches is not as great as that of the branches of Dictyo- 
nema flabelliforme and its thinner substance serves to distin- 
guish it from that species. It may be known from Bryograptus 
spinosus by its somewhat broader branches and its larger thece. 
A group of eight branches of an individual of this species is 
known,and from the fact that the cells on these branches are all 
turned in one direction it seems probable that the initial 
branches were far enough off to indicate a hydrosome of con- 
siderable size, of which this was a portion of one-half. 
Size. Hydrosome 40 or more mm. across, and about 50 + 
mm. long. 
Horizon and locality. In the black shales of Div. 3c with 
Clonograptus proximatus, at Navy Island. Scarce. This type 
collected by G. van Ingen. 
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