100 £&. SS. Morse—Brachiopoda a division of Annelida. 
washed with water, it undergoes a very slow decomposition, 
the volume increases a bubbles of hydrogen escape throug 
the water above. An ition of zine-amalgam or sodium- 
ie greatly accelerates the decomposition of the aie. 
the Adee putea formed on the surface of the mer- 
cury, gradually decomposing above and being renewed from 
below. 
Graham compares hydrogenium to the active modification of 
oxygen, and no doubt there is much analogy between them. 
We may distinguish three modifications of hydrogen; namely, 
(1) common nascent hydrogen formed by the action of sea 
amalgam on water, or by that of zinc and hydrochloric acid ; 
has a strong reducing power but cannot form hyaeooentale 
amalgam ; (2) common gaseous hydrogen which has at common 
temperatures only a very weak reducing power; and (3) hydro- 
genium. ‘There are reasons for believing that these differences 
may be expressed by the following formule: 
[O] OO 
[00]0 
Antozone Common oxygen Ozone 
a oxygen, B oxygen. y oxygen. 
HH)|H 
Common nascent or Common gg or Hydrogenium 
drogen. B hyd y hydrogen. 
Art. XV.—The Brachiopoda, a Division of Annelida ;* by 
Epwarp S. Mors. 
At a meeting of the Boston Society of Natural History, 
June ist, 1870, Mr. Edward S. Morse made a verbal communi- 
cation on the position of the Brachio la in the animal king- 
dom. He referred to the branch of Mollusca as it was under- 
sod ike, years ago, when misled by external characters, many 
worms, a and Spirorbis, and a group of Crustaceans, 
the Cirri were included with mollusks, and that from a 
proper ee of their characters these diverse forms had 
from Proceedings Boston Society Natural History. 
