XXVI 
SYNOPSIS OF GENERA. 
tubes, and at irregular distances tubes which have the same manner of growth 
as the primary rachis; this mode of growth is continued indefinitely, the 
fronds covering a comparatively large area. Cell tubes turning abruptly out¬ 
ward at their distal extremities and opening in an aperture parallel with the 
axis of the branch. 
Example: Reptaria stolonifera, pi. lxv, figs. 17-19. 
Hederella, Hall (Trans. Albany Institute, vol. x, p. 194. 1881). 
[Type, Alecto ? Canadensis, Nicholson.] 
Zoarium parasitic, consisting of a filiform tubular axis, with opposite or 
alternate lateral budding of simple tubular cells; also of lateral extensions 
continuing in the same manner of growth as the initial axis. 
Examples: Hederella cirrhosa, pi. lxv, figs. 12, 13. 
Hederella Canadensis , pi. lxv, figs. 1-8, 14 and 16 ? 
Hernodia, Hall (Trans. Albany Institute, vol. x, p. 196. 1881). 
[Type, Hernodia humifusa, Hall.] 
Zoarium parasitic, consisting of tubular, annulated cells, enlarging to near the 
aperture; increasing by lateral gemmation, and the buds continue growth in 
the same manner as the parent tube, so that comparatively large surfaces are 
often covered. 
Example: Hernodia humifusa, pi. lxv, figs. 20, 21. 
Botryllopora, Nicholson (Geological Magazine. April, 1874). 
[Type, Botryllopora socialis, Nicholson.] 
Zoarium consisting of small discoid bodies, occurring singly or in groups, 
connected by vesicular tissue, adherent to foreign bodies by their under surface. 
Cells tubular, disposed in double, radiating rows, forming alternating ridges. 
Intercellular space vesiculose. 
Example : Botryllopora socialis, pi. lxiv, figs. 3, 4. 
Note. —The restricted number of pages -for the foregoing Synopsis has made it necessary to give the 
briefest possible description in order to notice the entire number of genera in the volume. Much, there¬ 
fore, has been omitted, especially the comparisons and inter-relations of the genera. 
