OF DENISON UNIVERSITY. 
8i 
once distinguished by the celluliferous character of what might be 
taken for dissepiments, even if these should unite neatly. 
Common at Flint Ridge. ( Gracilis^ slender branches.) 
FENESTELLIDAE, King. 
Zoaria usually reticulate, poriferous on one side only, branches 
united by non-poriferous dissepiments or anastomosing; in the latter 
case there is never a division possible into stems and branches, so that 
no confusion with the Acanthocladiidce need arise. 
Genus CHAINODICTYON, gen. nov. 
Zoaria flabellate or perhaps infundibuliform, branches inosculat- 
ing, forming a loose net-work, the meshes of which are elongated, 
elliptical, or oval, somewhat variable (as the openings in the fronds 
of some Clathroporcd) . Branches flattened, sometimes even concave 
on the non-poriferous side. Without longitudinal striae, as far as 
known, but with very marked lunate striations or rather folds extend- 
ing across the non-poriferous sides of the branches, similar to the lines 
of growth seen on the epithecal membranes of Stictoporidcz. Cells 
in oblique intersecting rows which give rise to three less evident, rather 
irregular, longitudinal series. {Chaim, dictyon, net; alluding 
to the elongated large meshes of the zoarium.) 
Phyllopora, the nearest related genus, has rounded meshes; the 
branches are far less flattened on the non-poriferous side, and are 
finely striated longitudinally; on the poriferous side the cells have a 
more regular arrangement into longitudinal rows ; it occurs in older 
paleozoic formations; Chainopora maybe considered its later repre- 
sentative. 
VIII. Chainodictyon laxum, sp. n. 
{Plate VII, Fig. 8, a, b, c.) 
Meshes elongated, rhomboid, elliptical, oval, ovate, and obovate 
in the same zoarium, typically elliptical, about 2.5 mm. long and 1.3 
mm. wide. Branches narrow, about .3 to .38 mm. wide; the cells 
are arranged in diagonal rows ; longitudinally about 5 cells may be 
measured along the sides of the branches in a length of 2 mm. The 
