NORTH AMERICAN EARLY TERTIARY BRYOZOA. 437 



olocyst with tubules. The apertura (interior) is formed of a semilunar anter and 

 of a concave poster; the peristomice (exterior) is elongated, imbedded, provided 

 with a triangular rimule-spiramen. The ovicell is hyperstomial, buried in the distal 

 /ooecia, globular, salient, decorated with large tremopores; it opens largely into 

 the peristomie. The oral avicularium is adjacent to the peristomice and placed 

 somewhat obliquely; it is triangular, rather long, and provided with a pivot; the 

 beak is turned outward. 



Measurements. Apertura f^<z=0.15 mm. . , . r/ie=0.14- 0.16mm. 



,. , . N 4, -reristomice^, .-.-, nnn 



(interior) \la=Q.15 mm. \lpe= 0.18-0.20 mm. 



. fZ.2=0.90-1.00mm. 

 Zooecia , 



[h=OAOmm. 



Variations. The zooecial walls are relatively little thickened (figs. 19. -20. 21) ; 

 also the exterior aspect is rather constant. The variations observed are principally 

 those of the avicularium; it is often long and salient (figs. 14, 15), often short 

 (fig. 13), often worn (figs. 17. 18). The tremopores are large, but they are smaller' 

 when they are more numerous (figs. 16. 18). The zooecia are sometimes bordered 

 by a thread (fig. 14) which may become very prominent. 



The tangential section shows the frontal tremopores. Because of the general 

 convexity of the zoarium it is impossible to obtain a preparation which shows all 

 of them. In figure 21 the lateral tremopores occur alone and in the middle, the 

 subjacent olocyst appears. 



Affinities. This species differs from Enoplostomella rhomboidalis, in its zoa- 

 rial form, in the absence of large separating threads between the zooecia, and in 

 the much more globular ovicell. 



It differs from Enoplostomella lif/uJifcra, which is also vinculariform in the 

 absence of lateral tongues to the peristomice and in its oral avicularium of much 

 less strength. (Lav=0.25 mm. and not 0.40 mm.) 



Occurrence. Vicksburgian ("Chimney rock" of Marianna limestone) : One 

 mile north of Monroeville, Alabama (very common). 



Cotypes.C&t. No. 62594, U.S.N.M. 



ENOPLOSTOMELLA LIGULIFERA, new species. 



Plate 90, figs. 17-22. 



Description. The zoarium is free, cylindrical, sometimes bifurcated. The 

 zooecia are distinct, elongated, fusiform; the frontal is convex, thick, formed of a 

 tremocyst with tubules surmounting a thin olocyst with small scattered pores. The 

 apertura is very oblique and orbicular; the peristomice is large, elongated, pro- 

 vided with a wide, triangular, short rimule-spiramen, garnished laterally with two 

 salient, widespread tongues. The ovicell is hyperstomial, globular, salient, gar- 

 nished with tremopores; it opens largely into the peristomie. The avicularium is 

 very long, transversal, provided with a pivot; the beak is directed outward. 



