514 



LONSDALE ON EOCENE CORALS FROM N. AMERICA. 



bodies furnished with them were so thickened on the outer surface 

 that the processes became partially or wholly overlaid. These 

 characters are considered deserving of attention, as they may assist, 

 conjointly with other structures, in determining how far poly- 

 parians, at one period fixed and at another free, are capable of 

 being generically united. 



Localities. — Eutaw ; Wilmington ; Cave Hall. 



3. Endopachys alatum. 



Wedge-shaped, expanded at the base, irregularly ribbed ; about twelve pro- 

 minent, broad, simple lamellae, intermediate lamella? numerous, of variable 

 breadth, grouped, sides minutely tuberculated ; outer surface in the lower part 

 almost wholly occupied by small papilla?, with few intermediate foramina ; in 

 middle region, openings more numerous, in uppermost papilla? few, structure 

 reticulated ; ribs formed of similar structure ; thickening towards the base con- 

 siderable, traversed throughout by the foramina. 



Two Alabama eocene corals 

 exhibited characters which 

 demanded special attention. 

 One specimen represented by 

 figure a, and believed to be 

 generically allied to the 

 other delineated (fig. b. c,) 

 resembled closely the Tur- 

 binolia semigranosa of M. 

 Michelin (Icon. Zoophy. pi. 

 43. f. 2. 1845.) ; and it is 

 with fossils usually assigned 

 to that genus that the Ame- 

 rican coral must be com- 

 pared. In both the small 

 and larger specimens ' there 



a. Mature specimen of Endopachys ala- 

 tum fractured in the upper part. (Mag. 

 1|, linear ) 



b. Upper termination (Mag. twice, linear) 

 of a small coral belonging to the genus ; 



c. A side view of the same specimen 

 magnified rather less than twice. 



was a total want of a pedicle, or of a cicatrised detached 

 surface — the sharp, wedge-shaped lower termination of the 

 former being slightly concave, and beset with minute points, 

 while the same extremity of the large specimens, though thin, was 

 rounded, and uniformly coated with the small tubercles which 

 covered the general outer surface (see fig. c). To this extent, 

 therefore, a perfect agreement existed with T. crispa, T. sul- 

 cata, and T. mixta, but the resemblance proceeded no further. 

 In those species, recognised types of the genus, the external surface 

 was not modified or thickened by secretions either from within 

 or without ; whereas the Alabama coral was progressively altered 

 in aspect by the development of tubercles secreted through fora- 

 mina connected with the internal structure. Again, in the Tur- 

 binolias above mentioned, the lamellae preserved great simplicity of 

 arrangement under all conditions, while in the American coral they 

 were exceedingly complex in the full-grown state, varying greatly 

 in breadth, and united in groups : still farther, the boundary in 

 Turbinolia crispa, sulcata, and mixta, is also very simple, consist- 



