CERAMOPORID^E. 21 
Ceramoporella irregularis, n. sp. 
PI. IX, figs. 7-9. 
Zoarium incrusting, the type specimen growing around a crinoid column and consisting 
of two superposed layers of zocecia varying from one-third to 1 mm. in thickness. Zocecial 
apertures direct, arranged radially about the maculae, which are small and inconspicuous 
and consist mainly of mesopores. Zocecia usually angular, 4 to 5 in 2 mm., with thin 
walls, the posterior one-fourth, exhibiting the sharply elevated lunarium which is less over- 
arching and more erect than usual. Mesopores rather numerous, angular, thin-walled, 
irregular in size and shape. 
Vertical sections. show that the zocecia have a small axial region and a large peripheral 
zone. The walls exhibit the indefinite hazy structure transversely marked that is charac- 
teristic of the family as a whole and is known as ceramoporoid structure. A single dia- 
phragm is inserted in some of the zocecial tubes. Tangential sections bring out the luna- 
rium and the irregular zocecia and mesopores particularly. 
This interesting species is closely related to the Cincinnatian form, Ceramoporella distincta 
Ulrich, but differs in having a larger and more prominent lunarium, and more irregular 
zocecia and mesopores. Care must be taken to separate it from the associated Ceramopora 
hiagarensis, which it resembles externally in some respects. However, upon examination 
with the lens, the angular, thin-walled, direct zocecia and mesopores of the Ceramoporella 
contrast strongly with the thick-walled, oblique zocecia and long-drawn-out lunarium of the 
Ceramopora. 
Occurrence. — -Rather rare in the Rochester shale at Lockport, N. Y. 
Catalogue number, 35480, U. S. National Museum. 
Genus CCELOCLEMA Ulrich. 
The Niagaran rocks of New York and Indiana contain several new species of ceramopo- 
roids which in the present state of knowledge can only be referred to the Ordovician genus 
Coeloclema. These Silurian forms have several features in common which, with a careful 
study of this group, will probably cause them to be assigned elsewhere. Coeloclema was 
established for ceramoporoids having zocecia as in Ceramoporella, but differing in that the 
zoarium formed hollow branches lined internally with a striated epitheca. 
Coeloclema cavernosa n. sp. 
PL XXIII, figs. 10-13. 
Zoarium of hollow branches varying in diameter from 2 to 5 mm., lined internally with 
a striated epitheca; thickness of zoarium 0.5 mm. or less. Surface without monticules but 
rough on account of the projecting lunaria. Maculae small, solid, not a prominent feature. 
Zocecia arranged in regularly ascending diagonally intersecting rows, measuring along one 
of the rows, 5 zocecia in 2 mm. Posterior wall of zocecia raised, long drawn out, and over- 
arching the aperture, forming the prominent lunarium. Internal structure as in Ceramo- 
porella and related genera of the Ceramoporidae. 
The only associated hollow-branched species, Fistulipora tuberculosa (Hall), may readily 
be separated from the form just described by its very small, strongly bilobed zocecia and 
different internal structure. 
Occurrence. — Half a dozen specimens were found in the Rochester shale at Lockport, 
N. Y.; rare in the Osgood beds at Osgood, Ind. 
Catalogue number, 35471, U. S. National Museum. 
Genus SPATIOPORA Ulrich. 
Zoarium forming thin crusts, usually on Orthoceras; zocecia very short, nearly direct; 
apertures irregular, with blunt spines at the angles, no lunarium developed; elevated, 
elongated maculae usually a conspicuous feature. 
The following species agrees in all respects generically and is otherwise closely related to 
typical Cincinnatian forms, such as S. lineata Ulrich. 
