320 



MOLLUSCOIDEA— BRYOZOA 



PHYLUM V 



zoojcia grown back to back. Very abundant in the Jura, less common in Cretaceous 

 and Tertiary. 



Bidiastopora d'Orb. Like Diastopora, but the zoaria forming only narrow, parallel- 

 edged branches. Cretaceoiis. 



Reptomultisparsa, Cellulipora and Filicrisina d'Orb. Cretaceous. 



Diastoporina Ulricli. Ordovician. Hederella and Hernodia Hall ; and Beptaria 

 Rolle. Devonian. 



Family 3. Idmoneidae Busk. 



Zoaria forming free or adnate, variously compressed branches. Zocecial apertures 

 rounded, more or less elevated, usually arranged in transverse roios on two faces of the 

 branches ; sometimes the two faces are confluent. Dorsal surface of the branches without 

 zooecia, but often occupied by numerous small tubular pores, ivhich may also occur near 

 the apertures. Sac-like ovicells with but a single opening. Ordovician to Recent. 



Idmonea Lamx. Zoarium adnate with apertures opening in transverse series. 

 Jurassic to Recent. 



Grisina d'Orb. (Fig. 442). Zoarium erect, simple or branching. Branches 

 usiially triangular, two of the faces carrying the zocecial ajjertures, which are generally 

 arranged in alternating transverse series. Jurassic to Recent. 



Bisidmonea d'Orb. Quadrate, 

 simple or branching stems, bear- 

 ing zocecial apertures on all faces. 

 Cretaceous. 



Betecava d'Orb. Zoaria reti- 

 culated ; branches greatly com- 

 pressed laterally ; reverse side 

 occupied by an axial rod. Cre- 

 taceous. 



Bicrisina, Bitubigera, Bepto- 

 fascigera, Semiclausa, Sulcocava 



(Laterocava) d'Orb. : and Perqen- 

 Protocrisina exigiia ,, ^ ^, 



uirich. Trenton sella Oregory. Cretaceous. 



N.Y."'Branche"'o7a Phalangella Gray. Creta- 



large expansion, i^/i. ceoUS to Recent. 



Protocrisina Ulr. (Fig. 443). 

 Narrow, bifurcating branches, celluliferous on one side only. Zooecia sub -tubular, 

 with prominent circular apertures arranged in intersecting diagonal series. Small 

 pores, apparently communicating with interior of the zooecia, irregularly distributed 

 over both faces of the branches. Ordovician and Silurian. 



Family 4. Entalophoridae Reuss. 



Zoaria ramose ; branches free, sub-cylindrical, with 

 rounded and more or less prrominently exserted zocecial 

 apertures opening on all sides. (?) Without accessory or 

 interstitial pores of any kind. Ordovician to Recent. 



Entalophora Lamx. {Glavisparsa d'Orb. ; Pergensia 

 Walford) (Fig. 444). Zocecial tubes disposed about an 

 imaginary axis, and with rounded, more or less prom- 

 inent apertures. Jurassic to Recent. 



Fig. 442. 



Cnslna dorsata Hagenow. Uppermost 

 Cretaceous ; Maestricht. A, Branch, nat. 

 size. B, Upper, and C, Lower side, highly 

 magnified. 



Pig. 443. 



Fig. 444. 

 Entalophora vi'r- 



Spiropora Lamx. {PustuloiJora and Cricopora Blain- ^l^-^-- ^.^,?''' 



agenow. 



Fio. 445. 



Spiropora vcr- 

 ticilkita Goldf. 

 Upper Cretace- 

 ous ; Maestriclit 



e) {big. 445). Like the preceding, but apertures Plauen, Saxony. (after Hagenow). 



