108 



ON THE FOSSIIi CORALS OF THE 



mens are broken to pieces, a fragment from the upper part has a very 

 dissimilar aspect from another taken from the base, on accovmt of the 

 difference in the size of the tubes. The top of one of these large 

 colonies would furnish specimens exactly like Groldfuss's figure 4 c, 

 with cells of the same size, the same curve, and also with in general 

 only one row of pores, while the upper surface unbroken would give 

 4 5. Thus, according to my view all three of Groldfuss's figures re- 

 present colonies of a single species. Edwards and Haime, however, 

 have divided the species ; referring specimens in which the cells are 

 exceedingly unequal to i^. Forhesi, and those wherein there is no 

 great inequality to F. lasaltica. Their description does not differ 

 materially from that of Groldfuss, and it would be the better course 

 not to separate the species until a distinction can be pointed out. 



Eeturning to the small pyriform specimens, they can be traced in 

 another direction through a gradually changing series to elongated 

 cylindrical forms from one to two inches in diameter, and more than 

 one foot in length. These transitions can only be proved by a good 

 collection of such beautifully preserved specimens as are now in the 

 Museum of the Greological Survey. Fig. 8 represents the first step 

 in the passage from the cylindrical to the globose forms. 



As I have already stated, it is in these small specimens that we ob- 

 serve in the extreme the inequality in the size of the corallites. In 

 the large masses, the cells are more nearly equal, and smaller upon 

 an average than the large cells in the smaller. 



Notwithstanding all the above, I should not be at all surprised if 

 evidence should be procured hereafter to prove that both F. hasalticU 

 and F. hemispherica are inseparable from F. Gothlandica. The 



