234 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



species on account of the thickness of the mural rim and the elliptical form of 

 the avicularian opesium. 



Occurrence. Middle Jacksonian: Near Lenuds Ferry, South Carolina (rare) ; 

 Eutaw Springs, South Carolina (rare). 



Cotypes. Cat. No. 63991, U.S.N.M. 



AECHMELLA FILIMARGO Canu and Bassler, 1917. 



Plate 3T, figs. 3-5. 



1917. AecluiiclJa fllininrgn CANU and BASSLEK, Synopsis of American Early Tertiary 

 Cbeilostonie Bryozoa, Bulletin 90. United States National Museum, p. 29. pi. 3, fig. 5. 



Description. The zoarium incrusts Orbitoides. The zooecia are elongated, 

 distinct, separated by a furrow or united by their mural rims: the mural rim is 

 thin, incomplete, convex, distinct from the cryptocyst. The cryptccyst is shallow. 

 oblique toward the opesium, flat, finely granulose; the opesium is transverse, con- 

 stricted by two lateral teeth at the level of the rotary axis of the operculum; the 

 polypidian convexity projects but little; the opesiular indentations are large, round, 

 and symmetrical. The ovicell is endozooecial and small. The ancestrula is a 

 small zooecium, but otherwise identical with the others. The avicularium is inter- 

 zooecial, smaller than the zooecia. lozenge-shaped, with a small distal canal and a 

 round opesium. 



[7; ^=0.12 mm. 

 Measurements. Opesium ,, . . . . , 



1/0=0.16 mm. (including the opesiules) 



. . 



Marginal zooecia { , ,, 



[, 7 2=0.30mm. 



Affinities. This species differs from Rhaf/asostoma lewic/atum, in having an 

 endozooecial ovicell. It may be distinguished from Aedimelln c-rasshnargo by its 

 filiform mural rim. 



Very often the proximal border of the opesium is simply undulated and the 

 opesiules are visible only on account of the opesiular teeth. The opesia of the 

 ovicelled zooecia seem a little larger than the others. 



Occurrence. Upper Jacksonian (Ocala limestone) : West bank of Sepnlga 

 River, Escambia County, Alabama (rare). 



Cotypes. Cut. No. 62555, TJ.S.N.M. 



Genus MICROPORA Gray, 1848. 



1848. Hicropora GRAY, Catalog List British Animals in British Museum, pt. 1. Ceutroniae, 

 p. 115. 



The two opesiules, which are more or less constant, have the form of simple 

 perforations. Spines may appear. The ovicells are endozooecial, but very promi- 

 nent, and the small avicularia. which are situated proximally in the aperture, are 

 furnished with a complete crossbar (after Levinsen). Dietellae with few pores. 



Genotype. Micropora, (Flustra) corlacea Esper, 1791. 



Kcnige. Midwayan. Recent. 



