280 
PALEONTOLOGY OF NEW YORK. 
sisting of a main tube or axis from which proceed laterally, at more or less 
regular intervals, simple tubular cells, and at irregular distances other tubu¬ 
lar extensions which have the same manner of growth as the primary 
axis. This mode of growth is indefinitely continued, so that comparatively 
large surfaces are covered by the fronds. The cell tubes are sub-cylindrical, 
transverse section broadly oval, length from 2 to 2.50 mm., diameter .50 mm., 
turning abruptly outward at the extremity, the apertures opening on a line 
parallel with the axis of the branch and very broadly oval or nearly circular. 
Cells generally alternating, distant on the same side of the main axis from 
1 to 1.25 mm.; the angle of divergence from the axial tube is usually from 
thirty-five to forty degrees. Surface marked by numerous, very fine, sharp, 
transverse striations, and nearly equally fine longitudinal striae, often pre¬ 
senting a minutely cancellated appearance; on many of the cell tubes there 
are also more prominent annulations and wrinkles. 
On account of the frequent occurrence of the cell tubes, their margins are 
in contact for their entire length, the frond presenting a much more compact 
appearance than usual in species of this genus and frequently so closely resem¬ 
bling the genus Reptaria, that it is sometimes difficult to distinguish its generic 
relations. 
-Y- -Y- -V- -V- -V- -V' -V- -V- 
W'7v**7v*'7v**7'F'/V*W^Fw 
Formation and locality. Hamilton group, Darien Centre, Genesee county, 
N. Y. 
HeDERELLA MAGNA. 
PLATE LXV, FIG. 15. 
Hederella magna, Hall. Trans. Albany Institute, vol. x, p. 195. 1881. 
“ “ “ Report of State Geologist for 1883, p. 55. 1884. 
Zoarium parasitic, usually occuring on Cyathopliylloid corals, most frequently 
on Heliophyllum Halli; procumbent, attached for its entire length, consisting 
of an axial tube from which proceed lateral, simple, tubular cells, and at 
infrequent intervals tubular extensions having the same manner of growth 
as the primary axis; length of cell tubes from 2 to 3 mm , diameter a little 
more than 1 mm., transverse section broadly oval; at first rapidly expand- 
