51. CONTRIBUTION TO 



allites. These strhe are irregular, and generally more than their width apart. 

 They have the appearance of being minutely cancellated. This is the only 

 surface ornamentation observed, all the other specimens seen having a smooth 

 surface, or only showing faint costal striations. 



Horizon and Localities. — In the Keokuk group of the Lower Carbonian of 

 Crawfordsville and Edwardsville, Indiana, specimens figured with others in 

 the collection of Mr. G, K. Greene. - 



CERATOPORA AGGLOMERATA. N. Sp. (Grabau.) 



Plate 19. Figs. 22-25. 



Corallum compound, consisting of agglomerate masses, unattached except 

 basally. Corallites auloporoid, slightly curved, and gradually enlarging to- 

 wards the aperture which is circular. A short distance below the termination 

 of the corallite, one or two buds are given off, diverging at various angles; 

 sometimes extending acutely upward; frequently at right angles to the parent, 

 or occasionally extending downward. The buds themselves give off other buds 

 which may extend in all directions. Corallites frequently joined by epithecal 

 prolongations. Interior with circumferential cysts. Cysts rather sparingly 

 developed, but usuall3'" of fair size. Septal spines small, short and compara- 

 tively stout; in numerous vertical rows. 



Observations — This species is readily recognized by its singular branch- 

 ing corallites which form a confusedly agglomerate mass. The frequent rect- 

 angular divergence of the buds from the parent, gives rise to masses in which 

 corallites of the third generation, may grow in a diametrically opposite direc- 

 tion from that taken by corallites of the first generation. Sometimes from 

 crowding, a bud may grow in such a direction as to form a complete loop with 

 its parent corallite. Not infrequently a number of corallites, budding one 

 from the other, appear to form a ring around a corallite of an earlier genera- 

 tion which occupies the center. 



No ease has been observed in which there are more than two buds given off 

 at the same level, this being the usual number. In this respect the species is 

 like C. dichotoma, Grabau, but the buds are irregular as in C. distorta, Gra- 

 bau. In some corallites, however, a second series of buds is given off at a 

 higher level, and these, rebudding again, greatly increase the complexity of the 

 whole corallum. In some cases, however, the corallites grow to a considera- 

 ble length after giving off their first pair of buds, without producing a second 

 series. While the buds are most frequently given off in pairs, the two are not 

 always given off at precisely the same level, there being often a slight discrep- 



