ROCK SPECIMENS. 
ccli 
tinct from the commo chain coral of Gothland, and other countries. 
Lamarck has two species of this genus, namely, the common one, which is 
(rather unaptly) called by him C. escharoides ; and another, which he distin- 
guishes by the name of C. axillaris, though it appears from his reference to a 
figure in the Amcenitates Academicce, that he is speaking of Tubipora serpens, 
L., which is not a congener of, and can indeed scarcely be considered as 
belonging to, the same natural order with Catenipora. We may, therefore, 
look upon this arctic species as an imdescribed and anonymous one. I 
call it 
Catenipora Parn7; tubulis crassiusculis, compressis, collectis in laminas 
sinuatas varie inter sese coalitas, tubulorumorificiis ovatis saepe confluentibus: 
dissepimentis confertissimis. 
The space between the laminae is filled up by a yellowish calcareous 
mass ; the tubes themselves are converted into carbonate of lime, internally 
drused with minute crystals of the same substance. 
Very little can be inferred from the specimens of primitive rocks, 
gathered both in Prince Regent’s Inlet and Barrow’s Strait : they are, for 
the most part, fragments from rolled pieces, and consist chiefly of granite, 
mica slate, and quartz rock. There are, nevertheless, some among them, 
especially among those from the first-mentioned tract, which distinctly 
indicate primitive trap formation, such as granular and slaty hornblende 
rock, together with several varieties of syenite, and similar rocks, in which 
hornblende and feldspar form the predominating ingredients ; some of 
them enclosing massive and indistinctly crystallized epidote of either a 
yellowish or grass-green colour. Among some specimens found at Port 
Bowen, on the eastern coast of Prince Regent’s Inlet, may be specified a 
rolled piece of a mass, composed of flesh-red feldspar, greyish-white quartz, 
and a substance which is distinct from epidote, though it might easily be 
mistaken for it. According to an analysis, with which I have been favoured 
by J. G, Children, Esq., it is composed of silica 59.89, alumina 22.45, soda 
6.84, linie 4.85, oxide of iron 4.0, magnesia 0.67, oxide of manganese 0.16; 
