NIAGARA GROUP. 
159 
Genus CLATHROPORA {nov. gen.). 
[Latin, clathrum , a lattice, and pora , a pore.] 
Ramose or reticulate corals ; uniformly poriferous on both sides of the reticulate fronds, and 
on all sides of the stems and branches of ramose forms; apertures of cells more or less 
quadrangular, regularly arranged in series parallel to the direction of stems, or obliquely in 
quincunx order. 
The habit and general characters of the corals of this genus are similar to Retepora ; but 
the two sides are poriferous, and the form and arrangement of the cells differ from those of 
Retepora. The branching species differs from Stictopora in being celluliferous on all sides, 
and having the cells arranged between linear ridges or lamellae; while in that genus the 
branches are flattened, with non-poriferous edges, and the cells are not thus arranged between 
laminae. From Ph^nopora, as described under the Clinton group (page 46), it differs in the 
form of the cells, and the thickening of the stems and branches, a character which has not been 
observed in any species of that genus. 
A more critical examination of P. ensiformis , which likewise occurs rarely in the Niagara 
group, shows that it differs in some respects from the other species of Ph^nopora, and is more 
nearly allied to the following species of this genus. 
553. 1. CLATHROPORA ALCICORNIS. 
Pl. XL B. Fig. 4 a, 6, c. 
Stems cylindrical below and flattened above, bifurcating and variously branched, branches 
frequently bifurcating ; entire surface celluliferous ; apertures of cells quadrangular, rhomboidal 
or oblong, and variable in form at the divisions of the stem ; cells consisting apparently of 
simple tubes reaching to the axis of the stem and branches. 
This species is readily distinguished from Stictopora and Retepora, by the characters given 
under the generic description. In its mode of branching it is very peculiar, differing from any 
species described : the stem makes an abrupt bending at the point where each branch is given 
off, and the branches scarcely differ in size from the stem above and below. At the point o in 
fig. 4 a, one of the branches appear to have reunited to the stem, and a young shoot has com¬ 
menced growing from the junction. This reuniting or anastomosing of the branches does not, 
however, seem to be characteristic of the species. 
Fig. 4 a. A portion of the stipe and branches of an individual of this species, natural size. 
Fig. 4 b. A portion enlarged, showing the oblong quadrangular apertures. 
Fig. 4 c. An enlargement of another portion of the surface, showing a difference in the form of 
the apertures. 
Position and locality. In the shale of the group at Lockport. 
