ANTTTOZOA—HRXACORALLA. 



10 



the longer of which, unite in the center, where they often form a 

 pseudocolumella. No true columella or pali occur. Tertiary. 



134. S. marylandica (Conrad). (Fig. 163.) Miocenic. 



Compressed stems with short, rounded branches, or large 

 flattened lobate or digitiform expansions. Corallites averaging 

 5 or 6 mm. in diameter. Twelve large and a similar number of 

 smaller septa occur ; sometimes a third series. 



Abundant in the St. Mary's Miocene 

 formations of various parts of the Atlantic 

 coast. 



LIII. Flabellum Lesson/ 

 Simple wedge-shaped compressed corals 

 free or attached, with numerous septa, and 

 a compressed columella. A wrinkled epi- 

 theca sometimes with spinous processes 

 occurs. Tert.-Recent. 



135. F. cuneiforme Lonsdale. (Fig. 164.) 



Eocenic to Oligocenic. 



Base with a short prolongation of attach- 

 ment ; exterior of compressed wedge- 

 shaped structure marked by strong ridges 

 or costae which are largest in the middle. 

 First three cycles of septa form the colu- 

 mella by fusion of their inner margins. 

 Claibornian, Jacksonian and Vicksburg- 

 ian groups of South Carolina, Alabama, 

 Mississippi, Louisiana,Arkansas and Texas. 

 Several distinct varieties are recognized. 



FlG. 164. Flabellum cune- 

 iforme, two varieties, with 

 calyx of F. lerclii (after 

 Vaughan, Mon. U.S.G. S.). 



LIV. 



Platytkochus Milne-Edwards & 

 Haime. 

 Simple cuneiform corals, with a colu- 

 mella formed of the fused inner edges of the septa. Externally 

 the septa are represented by thick costae, while within the outer 

 wall their margins are carinated. Tertiary. 



136. P. stokesi (Lea). (Fig. 165.) Eocenic. 



Small, with the base drawn out into a wedge nearly as wide as 



the coral above. Septa and costae 24, nine of which on the mid- 



