G. M. Ehlers — New Species of Tetracoralla. 463 



the exception of the cardinal one. This septum is poorly 

 indicated in the fossula, which is indicated on both lower 

 and upper sides of the specimen (see f, figs. 2 and 3). A 

 fissure, probably formed by the solution of the cardinal 

 septum, is readily seen in the central part of the fossula 



Fig. 2. 



Fig. 2. — View of the type specimen of Heterolasma foerstei from below, 

 showing the character of the outer surface of the corallum, double tubular 

 construction of the radiciform processes, a tabula and the position of the 

 fossula. Natural size. 



as shown on the lower, broken side of the specimen. A 

 part of the septum may be represented by a low, sharp- 

 crested ridge that extends towards the interior of the 

 coral, for a distance of 3 millimeters, from the inner end 

 of the fissure. The cardinal septum is not definitely 

 recognizable in the fossula on the upper side of' the 

 corallum. Within the fossula, which would exhibit con- 



