110 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



The frontal is a very thick olocyst bearing opesial avicularia and 

 some scattered pores. The opesium is small and has the form of the 

 aperture. The ovicell is hyperstomial, buried in the parietal thick- 

 ening; it is closed by the operculum. 



Genotype. — Frurionella parvipora Canu and Bassler, 1925. Upper 

 Cretaceous of Tennessee. (PI. 94 fig. O.) 



Fig. 25. — Genus Gephyrotes Norman, 1903 



A-F. Gephyrotes nitido-punctata Smitt, 1868. A. Zooecium, X19 (after Smitt 

 1868). B. Zooecia, showing avicularia (av) ovicell (ov) and spiramen (sp) 

 (after Nordgaard, 1895). C. Middle bars of the zooecium; a, lumen; b, c, union 

 of the arched costules at their extremity; d, median line of the zooecium. D. The 

 anterior portion of a zooecium to show the structure of the bridge and oral 

 opening; a, bifurcated costule; b, solid outspread costule; c, spiramen; d, lateral 

 foramen; I, lumen; Ip, lumen pore (after Norman, 1903). E. Costular system, 

 X83 (after Nordgaard, 1903); cl, loop of the costule; la, lacuna; lp, lumen pore. 

 F. Diagram of a zooecium and two avicularia, from above, X85. p, pclmatidium; 

 b, proximal apertural spine; a, bifurcated apertural bar; c, costa (after Lang, 

 1922). 



This new genus differs from Foveolaria Busk, 1884 (see pi. 94, figs. 

 P, Q) in its ovicell closed by the operculum and exteriorily invisible. 

 The other characters are identical. 



Family SYNAPTACELLIDAE Maplestone, 1911 



No ovicells. The zooecia are ovoid, with gymnocyst, arranged 

 more or less obliquely; the opesium is bordered by a salient mural 

 rim; the basal wall bears three large septulae. The colonies are 

 articulated and radicellate. 



