270 



MOLLUSCOIDEA BRYOZOA 



SUB-KINGDOM V 



Interstitial vesicles filled by a dense calcareous deposit near the surface. Silurian and 

 Sub-Carboniferous. 



Meekopora, Ulrich (Fig. 444). Zoaria bifoliate, sometimes branching, the median 

 laminae thin, flexuous. Oblique apertures all directed toward the distal margin of 



FIG. 444. 



Meekopora eximia, Ulr. Chester Group; Monroe Co., 111. A, Specimen 

 from the side and edge, 3/ B, Surface of same, 7/ x . c, Portion showing 

 ovicell, 14 /i (after Ulrich). 



FIG. 445. 



Strotopora foveolata, Ulr. 

 Keokuk Group ; Bentons- 

 port, Iowa. Part of ex- 

 pansion, 3 /4, and surface of 

 same, 7/j, showing zocecial 

 apertures and broken ovi- 

 cells (after Ulrich). 



the zoarium or branch, 

 often recurved. Ovicell 



FIG. 446. 



Buskopora dentata, Ulr. 

 Hamilton ; Falls of the Ohio. 

 Portions of surface, 7 fa and ^/j 

 (after Ulrich). 



bound the hexagonal 

 obsolete. Devonian. 

 Pinacotrypa, Ulrich ; 



Lunarium moderate or obsolete ; diaphragms numerous and 

 rather large, showing at the surface as a convex space with a 

 small apical opening. Sub-Carboniferous. 



Strotopora, Ulrich (Fig. 445). Zoaria ramose, with 

 irregular branches. Large, abruptly spreading cells (re- 

 garded as broken ovicells), distributed among the zooecia on 

 ordinary specimens ; when perfectly preserved they appear 

 as strongly convex elevations with a small opening on one 

 side. Devonian and Sub-Carboniferous. 



Lichenotrypa, Ulrich. First stages like Fistulipora, after 

 which large spines and irregular thin walls are thrown up 

 about the apertures. Devonian. 



Buskopora, Ulrich (Odontotrypa, Glossotrypa, Hall), (Fig. 

 446). Like Fistulipora, but lunarium remarkably developed, 

 projecting as a strong, bidenticulate process nearly half 

 across the aperture. Devonian. 



Selenopora, Hall (Favicella, Hall). Zoaria laminar, en- 

 crusting. Interzoo3cial spaces occupied by two series of 

 small vesicles, separated by strongly elevated walls. These 

 in which the zocecial apertures are situated. Lunarium 



(?) Botryllopora, Nicholson. Devonian. 



Family 11. Ceidae. d'Orbigny. 



Zoaria ramose, bifoliate, or urn-lamellate. Zooecia tubular, sub-equal, their walls thin at 

 first, but thickening gradually toward the periphery, where the cavity suddenly dilates in 

 such manner that the rounded or elliptical aperture lies at the bottom of an hexagonal 

 depression. Interstitial cells wanting. Cretaceous. 



The systematic position of this family is highly problematical. It appears to have certain 

 affinities with the Trcpostomata, but its removal to that vicinity is hardly feasible until a 

 thorough comparison of Palaeozoic and Mesozoic Bryozoans shall have been made. 



Semicea, d'Orb. (Reptocea, d'Orb., p.p.) ; Discocea, Pergens. 



Cea, d'Orb. Zoaria forming flattened branches or broad lamellae, celliferous on 

 both sides. 



