NORTH AMERICAN EARLY TERTIARY BRYOZOA. 467 



Affinities. The presence of the very salient avicularian mucro characterizes 

 quite well this species and permits us to differentiate it from the other large 

 costtilate species such as Smittina colum, S. yrandifossa, and S. corona fa. 



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

 south of Jackson, Alabama (common) ; west bank of Conecuh River, Escambia 

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

 Alabama (rare) ; near Claiborne. Monroe County. Alabama (common). 

 No. 64300, U.S.N.M. 



SMITTINA RETICULOIDES, new species. 



Plate 96, figs. 1-9. 



Description. The zoarium is free and bilamellar; the fronds are narrow or 

 wide, flat or undulated; the two lamellae back to back are inseparable. The 

 zooecia are elongated, distinct, narrow, fusiform, separated by a thread more or 

 less salient; the frontal is flat surrounded by a line of triangular areolar pores 

 numerous and quite large. The apertura is semilunar with a proximal border 

 somewhat convex; the peristomice is oval and irregular; the peristome is little 

 salient quite wide, smooth, enlarged at the base to bear the median avicularium. 

 The ovicell is globular, salient; it is formed of a small circular area perforated 

 by some large pores and with a large smooth collar ; it is hyperstomial, placed on 

 the distal zooecia and it opens into the peristomice. The median avicularium is. 

 small, triangular, with pivot, the beak above; it is placed on a thickening of the 

 peristome. 



,, . rZ3=0.70mm. 



Measurements. Zooecia/ , 



Variations. The pleurocystal calcification is very intense and gives to the 

 zooecia the most fantastic aspect sufficiently represented by figures 4, 5, 6. We 

 have been successful with two tangential sections. The first (fig. 9) is taken at the 

 level of the olocyst where one sees the elements irregularly grouped around the 

 median axis; the areolae are large and round. The second section was made a 

 little nearer the surface (fig. 8) ; it gives the construction of the interareolar 

 costules, the elements of which are grouped transversely. 



Affinities. This species is very close to the recent Smittina reticulata Mac- 

 Gillivray, 1842 ; it differs from it in the area of the ovicell which is much smaller, 

 ornamented only with some large pores and in the median avicularium which is 

 much smaller and always placed on a thickening of the peristome and not on the 

 frontal itself. 



It differs from the variations of Smittina telum with very small avicularia 

 in the much larger number of areolae (10) and in a less zooecial width (0.30 and 

 not 0.40 mm.). 



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

 mile north of Monroeville, Alabama (very common). 



C'otypes.Cat. No. 64309, U.S.N.M. 



