178 The American Geologist. ^-^r^K 1903. 
Virginia. A striking addition comprises many new species 
of cystids and crinoids. Of Sphaerocystitcs iiiultifasciatus 
several thousand specimens are at hand, and of Camarocrinns 
n'^any hundred individuals, some of which have a diameter of 
five inches. Bryozoa and ostracods are other characteristic 
elements of the Manlius, and its fauna is Siluric in facies. Out 
of this fauna some of the Helderhergian life developed, but the 
latter fauna also received many new immigrants towards the 
close of the Coeymans. It is these two elements, both derived 
from the North Atlantic, that together make up the Helder- 
hergian fauna. 
Thickness of Manlius. Along the eastern side of the Hel- 
derberg mountains and east of the Hudson river at Becrafts 
mountain, the Manlius is not fully developed ( 50-57 ft. ), and 
these younger deposits were laid down after the Cobleskill 
fauna had invaded southeastern New York. Along the west- 
ern side of the Helderbergs about Schoharie there is a far bet- 
ter development (91 feet), and the full series is seen in Litch- 
field township (no feet). At Port Jervis, New York, the 
thickness is 126 feet, and throughout Pennsylvania, Maryland 
and West Virginia it varies between 100 and 145 feet. This 
variation, however, is probably due isomewhat to interpretation, 
since, in a continuous series of like deposits correlated over a 
wide area, the faunal occurrences cannot be depended upon 
to hold the same plane throughout. In a general way, the 
average thickness for the Manlius mav be taken as no feet. 
EDITORIAL COMMENT. 
A NEW BUILDING FOR THE NATIONAL MUSEUM 
AT WASHINGTON. 
Among the bills passed during the closing hours of the re- 
cent Congress was one providing for a new building for the 
U. S.' National Museum, a matter in which, it is reasonable 
to suppose, the readers of this journal will have more than a 
passing interest. 
The present National Museum building, as is well known, 
is a cheap afifair, costing only about $250,000, erected in 1881 
to meet the emergencies of the acquisition of large collections 
from the Centennial Exposition in 1876. It was long ago ap- 
