NORTH AMERICAN EARLY TERTIARY BRYOZOA. 439 



zoarium. We do not think that it would be of any advantage to create a special 

 genus for this particular arrangement as the functions are exactly the same as 

 those of the other Enoplostomella. We can not logically separate it without a 

 complete study of the ovicell. 



The species differ from Enoplostomella magniporosa in its much smaller 

 tremopores, and its less wide zooecia. 



Occurrence. Vicksburgian (Marianna limestone) : West bank of the Conecuh 

 River, Escambia County, Alabama (very common) ; Murder Creek, east of Castle- 

 bury, Conecuh County, Alabama (very common). 



Cotypes.Cnt. No. 64295, U.S.N.M. 



ENOPLOSTOMELLA MAGNIPOROSA, new species. 

 Plate 89, figs. 15-20. 



Description. The zoarium is free, bifurcated, compressed, formed of four 

 longitudinal rows of zooecia arranged on one side only; on the dorsal face the 

 zooecia are separated by projections and ornamented with large tremopores. The 

 zooecia are distinct, elongated, hexagonal ; the frontal is flat or convex and formed 

 of a tremocyst with very large pores. The apertura is suborbicular ; the peri- 

 stomice is elongated and is provided with a wide and rounded rimule-spiramen. 

 The ovicell is hyperstomial, small, salient, ornamented with tremopores. The 

 avicularium is placed almost within the peristomie ; it is oval, provided with a 

 pivot ; the beak is directed outward. 



Measurements. Peristomice(/tpe=0.20mm. 7 (3=0.75 mm. 



(exterior) [lpe=Q.18 mm. a ife=0.55 mm. 



Variations. On the young branches (fig. 19) the avicularium is not placed in 

 the peristomie and the zooecia are more convex and are separated by furrows. We 

 have found only the single ovicell figured, and on a young branch (fig. 19). The 

 tremopores, by their coalescence, give to certain zooecia a fantastic aspect (fig. 16). 



Affinities. The zoarium has the aspect of that of Enoplostomella vallata; it 

 differs from it in the size of its tremopores and in its avicularium placed within 

 the peristomie. 



Occurrence. Yicksburgian (Byram marl) : Byram, Mississippi (common). 



Cotypes.C&t. No. 64289, U.S.N.M. 



Genus SCHIZEMIELLA Canu and Bassler, 1917. 



1917. Schizeniiella CANU and BASSI.EK, Synopsis American Early Tertiary Cheilostorue 

 Bryozoa, Bulletin 96, United States National Museum, p. 47. 



The frontal of the ovicell is very fragile. The apertura is schizoporellidan 

 with wide rimule. The rimule-spiramen is inconstant. The tubules are reunited 

 on their commonage. 



Genotype. Schizemiella claibornica Canu and Bassler, 1917. Claibornian. 



