124 PA[.JvONTOLOOY OF NEW-YOBK. 



racter, but in its solid slate this feature can not often be observed. In the specimen described, 

 it is impossible to decide whether the rays are spiniform or laraelllform ; and therefore it is 

 still possible that it may have the character of Favistella, though its constricted growth pre- 

 sents a different feature from any thing yet observed in that genus. 



Fig. 2 a. A fragment of a hemispheric mass, natural size. 



Fig. 2 i. A portion of the same enlarged, showing the constricted growth at intervals. 

 Fig. 2 c. A transverse section of the same enlarged, showing the stellate character of the ends 

 of the columns. 



The following figures are from small hemispheric forms, apparently of the same species as 

 the preceding. 



In the open cells there is a confused stellate structure visible, but so minute that it is scarcely 

 po.ssible to decide more than that the rays appear to be spiniform, and like those in the pro- 

 ceding species. In the solid specimens of this form I have found no rays. Although having the 

 character of growth and form of the CluP-tetes before described, tViis is clearly distinct in the 

 size of the cells and columns, and is probably identical with fig. 2 a - c. 



Fig. 3 a. A small hemispheric form of this species. 



Fig. 3 b. The base of the same, showing its mode of growth upon the valve of an Ateypa. 

 Fig. 3 c. Profile view, showing the form and elevation. 



Fig. 3 d. The base of a larger specimen, which commenced its growth upon a small shell. 

 Fig. 3 e. A portion of the surface enlarged, showing the form and apparent stellate character of 

 the cells. 



Position and locality. In the shale of the Niagara group at Lockport and elsewhere. 



(Stale Collection.) 



Genus FAVOSITES. 



When the introductory remarks to the corals of this group were printed, I had not detected 

 in any specimens examined the unequivocal evidence of pores in the walls of the cells ; and in 

 all but a single specimen of this family, I had found evidences of rays or lamella;. I have, 

 however, been able to prove the existence of the genus at this period, though in New- York it 

 holds a very subordinate place, so far as number of individuals or dimensions of the masses is 

 concerned : indeed it would be almost overlooked among the great number, and more con- 

 spicuous character, of the corals of the genera AsxROCEniuM and IIeliolites. On a farther 

 examination of the specimens sent to me from Milwaukie by Mr. Lapham, I have found a 

 species apparently identical with the one from Niagara ; and likewise, in the same association, 

 another species of very distinct character, so that we may regard the genus as being represented 

 in two species at this epoch. It now becomes a matter of some interest to ascertain the cha- 

 racteristic differences between this species, the one in the Pentamcrus galcatus limestone, and 

 the one in the Onondaga limestone, all of which approach in character the F. golhlandica, 

 but wliich are, in their habit and mode of growth, distinct species. 



