SUB-ORDER D CHILOSTOMATA 287 
Family 7. Membraniporidae.  Busk. 
Zoarium calcareous or membrano-calcareous, encrusting or erect, in the latter case bifoliate, 
or sub-cylindrical.  Zowcia placed side by side, and forming an irregular continuous 
expansion, or im linear series. Margins raised, the depressed front more or less 
membraneous. Cretaceous to Recent. 
Membranipora, Blainv. (? Marginaria, Roemer ; (?) Dermatopora, Hagw.), (Figs. 477, 
478). Zoaria encrusting, calcareous, or sub-calcareons. Zocecia arranged irregularly or 
in rows, without a calcareous Jamina on the front, or only partially covered by one, 
leaving a variously shaped aperture. 
Family 8. Cribrilinidae. Hincks. 
Zoaria encrusting or erect. Zowcia having the front wall more or less fissured, or 
traversed by radiating furrows. Cretaceous to Recent. 
Membraniporella, Smitt (Fig. 479). Zoaria encrusting or rising into free foliaceous 

as exw \f iO ~ 
ay ne =f ~ 
= E mat AADC) 
= & ayer 
Ry ES et 
te Si aCe = 
ne = hte = 
WE SOS Shi 
es a NE > 
BS 

% AN ~~ 
u DN aR 
f — dN gs Sal. 

Fic. 480. 
G. 479. ‘nent hone Tig 
Fic. 47 Cribrilina — Heer- 
Membraniporella manni, G. and H. 
Fic. 478. 
Membranipora plebeia,  Abbotti, G. and H. sp. Post-Pliocene ; 

Fic. 477. 
G. and H. Cretaceous; sp. Cretaceous ; Santa Barbara Co., 
Encrusting zoarium of Membranipora, N. J. Several cells N.J. Zocwciahighly Cal. Zocecia highly 
with non- calcified zocecial walls. highly magnified (after magnified (after magnified (after 
Magnified. Gabb and Horn). Gabb and Horn). Gabb and Horn). 
expansions, sometimes consisting of superimposed layers. Zocecia closed in front by 
a number of flattened calcareous ribs more or less consolidated 
centrally. Cretaceous to Recent. 
Cribrilina, Gray (Fig. 480). Zoaria usually encrusting. Zocecia 
having the front more or less occupied by radiating or transverse 
rows of punctures, each row in a furrow; orifice semi-circular or 
sub-orbicular. Cretaceous to Recent. 
Family 9. Microporidae. Smitt. 

Zoecia having the front wall entirely calcareous; usually with Fic. 481. 
short, elevated margins, fissures, or perforations. Cretaceous to Recent. Gan saoaes 
Micropora, Gray (Fig. 481). Zoaria encrusting. Zocecia with Recto eat weal 
prominent raised margins; the front depressed, with a perforation highly magnified 
at each upper angle below the semi-circular or rounded orifice. Gorn). Gabbe ane 
Cretaceous to Recent. 
Steganoporella, Smitt ; Setosella, Hincks. Recent. 
