NORTH AMERICAN EARLY TERTIARY BRYOZOA. 745 



Valuations. The zoarial variations are in rapport with the substratum. On 

 the shells, the branches are always longer and the zoaria more complete; on the 

 algae the branches are broken and detached from one another in fossilization. 



The aspect of the ovicell varies with the width of the branches and the number 

 of the tubes surrounded. 



Occurrence. Vicksburgian (Marianna limestone) : Salt Mountain, 5 miles 

 south of Jackson, Alabama (very common) ; near Claiborne, Monroe County, 

 Alabama (rare) ; Murder Creek, east of Castlebury, Conecuh County, Alabama, 

 (rare) ; west bank Conecuh River, Escambia County, Alabama (rare). 



Vicksburgian (Red Bluff clay) : One-fourth of a mile west of Woodwards, 

 Wayne County, Mississippi (rare). 



Cotypes.Cnt. Nos. 65383, 65384, U.S.N.M. 



DIAPEROECIA WALCOTTI, new species. 



Plate 154, figs. 10, 11. 



Description. The zoarium has the form of a multiserial Proboscina; it 

 incrusts orbitoid foraminifera in clavate branches. The tubes are distinct, cylin- 

 drical, very irregularly arranged, slightly striated, terminated by a peristomie 

 little salient and bent upward ; the peristome is thin, orbicular, horizontal. The 

 ovicell is little salient; the oeciostome is adjacent to a normal tube. 



Measurement. Diameter of the peristome 0.10-0.12 mm. 



We dedicate this species to Dr. Charles D. Walcott. Secretary of the Smith- 

 sonian Institution. 



Occurrence. Vicksburgian (Marianna limestone) : West bank, Conecuh 

 River, Escambia County, Alabama (rare). 



Holotype.C&t. No. 65385, U.S.N.M. 



Genus DIPLOSOLEN Canu, 1918. 



1918. Diplosolcn OANU, Les ovicelles des bryozonires cyclostomes. Bulletin Societe 1 Geologi- 

 que de France, ser. 4. vol. 16. p. 329. (Proposed for Diplopora JTTI.I.IEN, 1S8C, pre- 

 occupied. ) 



Adventitious tubules are present. The oeciostome is isolated. 12 tentacles. 

 Genotype. Diplosolen (Berenicea} obelhtm Johnston, 1847. 

 Range. Senonian-Recent. 



According to Waters the tubules are developed at the same time that a second 

 calcareous layer is superposed on the normal skeleton. 



The previously described species belonging to this genus are: 



Berenicea obelia Johnston. 1838. Helvetian-Recent. 



Reticidipora intricata Smitt, 1867. Recent. 



RcficuHpora transccnrtata Waters, 1884. Priabonian. 



Diastopora compacta Canu, 1909. Lutetian. 



Diastopora lineata Gabb and Horn, 1865. Cretaceous (Vincentown). 



Diastopora obclioides Pergens, 1889. Coniacian. 



The term " Diplopora " of Jullien has been preoccupied two or three times. 



