GRABAU: MONILOPORIDAE. 
411 
Cladochonus crassus Iiofe, Geol. mag., 1869, vol. 6, p. 352, fig. 
2, 3, 4, 4a. 
Monilopora crassa Nich. and Etli. Jr., Geol. mag., 1879, vol. 0, 
p. 293, pi. 7, fig. 2, a-f. 
Monilopora crassa Nicli., Tabulate corals of the Palaeozoic period, 
1879, p. 223, fig. 32 a-f. 
Description. “Irregularly dichotomous; branches thick, conical, 
short; slender at their origin, expanding rapidly; surface smooth.” 
“ This is by much the largest species of this group I have seen; it 
is common in the shales of several localities; it most nearly resem¬ 
bles the J. ( Jania = Cladochonus ) hacillaria , M’Coy, from which 
it differs in the great thickness and conical form of the branches. 
Length of specimens usually from one to two inches; length of 
branches about three lines ; diameter of branches at base usually 
about one line, at extremity one line and a half.” (M’Coy.) 
This description v r as evidently made from free growdng speci¬ 
mens. From one to three branches are given off from the earlier 
corallites. This species is frequently found growing around a 
erinoid stem, and liofe has made some interesting observations on 
the effect which such attachment produces on the erinoid column. 
According to him, a local enlargement or swelling is caused, by the 
growth of the coral, in the affected portion of the erinoid stem, 
vdiicli grow r s so as to enclose the coral, until finally the apertures 
of the corallites alone are visible. 
Rofe also discovered the reticulate structure of the wall, but 
Nicholson and Etheridge were the first to recognize its import. 
The presence of this structure, and the absence of tabulae, caused 
them to take this species out of Cladochonus, and erect for it Moni¬ 
lopora. According to their figures, the reticulate structure is v T ell 
developed in the v r all just about and below the expanded calyx. 
The lacunae are of nearly equal width with the subequal partitions, 
and the trabeculae are disposed at short and very regular intervals. 
Formation and locality. This species is at present known only 
from the Carbonic limestone of Great Britain and Ireland. 
Moxi lopora beechert, sp. nov. Plate 1, figs. 2, 3. Plate 2, figs. 
1-5. 
Description. Corallum regularly "branching or forming a con¬ 
fused mass of intergrown tubes, which branch and repeatedly unite, 
