122 EUGENE AND LOWER OLIOOCENE CORAL FAUNAS. 



OCULINA HARRISI Sp. nOV. 



PI. XII, figs. 9 aud 9a. 



This species is based on one specimen, the end of a branch, but it is 

 very well pre8er^•ed. 



The length of the branch is 85 mm.; diameter of its lower end, IT) 

 mm., of its upper end, II mm. The branch tapers but little and has a 

 blunt termination. The cosnenchyma is very solid; its surface is marked by 

 rather fine, low, granulated strite. The calices are distributed in rather 

 regular spirals; the usual distance between two, measured on a spiral, is 

 4 mm., but in one exceptional case the distance is \0 nun. The margins are 

 thin, project abruptly about 2 mm. above the coenenchyma; some are lower, 

 aud one is 3.5 mm. high. Externally the corallite walls are marked bv 

 rather broad, low costse, alternating in size and cori-esponding to all cycles 

 of the septa. The average diameter of the calices is 5 mm.; the smaller 

 ones are 4.5 mm., and one large one has a diameter of 0.25 mm. There is 

 practically no difference in the diameter of the corallite at the ccenenchymal 

 surface and at the calicular margin. Calices deep, wide open. Septa thin, 

 weak; a common arrangement is 14 prinei})al and 14 small septa, i. e., three 

 complete cycles in six systems, and four of the fourth cycle intercalated in 

 the two half systems on each side of the uppermost primary. Two septa 

 of the third C3'cle usually reach the columella in the two half systems on 

 each side of the uppermost primary. These two tertiaries and the second- 

 aries may be more prominent than the primaries. The margins are finely 

 and regularly dentate. The pali are merely arched lobes near the inner 

 terminations of the larger septa. They are usually distinct, but sometimes 

 are confused with septal dentations; in some cases they are very broad. 

 They are thin, and have granulated sides. Columella very poorly developed, 

 formed by the lax fusion of the inner septal terminations. Dissepiments, 

 if present, very rare. The calices fill up from below and obliterate the con- 

 nection with the axial corallite. 



Locality. — Red Bluff, Mississippi. 



Geologic occurrence. Red Bluft Ijcds. 



Type. — United States National Museum. 



The species is characterized especially by (1) the blunt termina- 

 tion of the branches, which taper very slightly toward the apex; (2) the 



