DESCRIPTIONS OF SPECIES. 115 



minute sharp transverse undulations, 10 to 14 principal septa, between 

 each pair of which are one or three septa of the higher cycles. Columella 

 poorly developed. 



Locality. — Red Bluff, Mississippi. 



Geologic occurrence. Red Bluff beds. 



Types, — From collection of T. H. Aldrich in the United States National 

 Museum; and United States National Museum. 



ASTROHELIA BURNSI Sp. nOV. 



PI. X, figs. 3 to 3b. 



Form ramose, branches of the type material small, 8 mm. in diameter, 

 cross section subcircular. Coenenchyma solid; ratio of diameter of axial 



3 5 



corallite to that branch ^-. Surface of coenenchyma striate, striae not 



very prominent. Calicular mai'gin usually elevated from 1 to 2 mm. above 

 the coenenchyma. Corallites arranged in irregular spirals. Distance 

 between corallites, from 2 to 3 mm. ; may be as much as 4 mm. Diameter 

 of calices, from 2.5 to 3.5 nun. Calice near terminus of a branch may reach 

 5 mm. in diameter. Costie corresponding to all cycles of septa, low, flat, 

 becoming irregular on the coenenchymal surface, with a tendency to be 

 nodular, densely granulate; granulations small. Calicular fossae shallow, 

 filling up from below with secondary deposit, connection with axial coral- 

 lite being obliterated. Dissejoiments present, but very few. Septa thin, 

 weak; arrangement is decidedly irregular; a common scheme in calices 2.5 

 mni. ill diameter is eight principal alternating with as many smaller ones. 

 In the larger calices there may be twelve principal alternating with as many 

 smaller ones, i. e., in three complete cycles. The calice in PI. X, fig. 3b (4.5 

 mm. ill diameter), shows such an arrangement. Margins of septa iiTegularly 

 dentate; no pali, an occasional paliform lobe; sides granulate, the granules 

 iiTegular in size and distnbutiou. Columella very poorly developed, formed 

 by the loose fusion of the inner terminations of the septa or processes from 

 them. Some calices, such as the one figured, are practically devoid of even 

 the false columella. 



Locality. — Jacksoii, Mississlppl. 



Geologic occurrence. JacksOlliaU StagC. 



Type. — From collection of T. H. Aldi'ich in the United States National 

 Museum. 



