DESCRIPTIONS OF SPECIES. 107 



(', larger than variety a, and the costpe are more })roniinent and mf)re acnte, 

 represented by Ph VIII, fig-. 12. The intergradation between all tlie ft)rm3 

 is complete. 



This species is very close to ParacyatJms crassus M.-Edw. and H./ 

 from the English Bracklesham beds. I was able to examine specimens of 

 Pantcyatlms crassus in the British Musenm (Natural History). The size, 

 character of costse, and general external appearance ftirnish no criteria for 

 specific difi"erentiation. The jjali seem to furnish a good basis for separa- 

 tion. In I', crassus they are thin, weak, transversely fluted, and have a 

 small inner tooth. The paliof P. alternatus, as PI. VIII, fig. 11a, shows, are 

 stout, with a strong- distinct inner lobe. Should this character ultimately 

 prove insutficient for the diff"erentiation of the species, P. alternatus must 

 become a synonym of P. crassus. 



PARACYATHUS GKANTJLOSUS sp. DOV. 



PI. VIII, figs 15 to 15b. 



This species is extreme!}' close to P. alternatus; therefore a difterential 

 diagnosis is given. The two ultimately may be miited. The general form 

 is indicated by the figm-e. The view of the calice from above, looking down 

 upon the columella and pali, is characteristic of the genus. The pali are 

 undulate, granular, and some have small wing-like lateral expansions. 



The transverse outline of the calice in P. alternatus is elliptical, while 

 in P. granulosus it is practically circular. With increasing height P. alterna- 

 tus increases more rapidly in diameter tlian P. gru)iidosus ; therefore the base 

 of attachment is proportionately larger in the latter species. The costse 

 of P. granulosus are not prominent, not very acute, not strongly alter- 

 nated in size, and are densely and minutely granulate. In P. alternatus a 

 deposit of callous is laid down upon the original costse on the lower portion 

 of the corallum. This callous is costate, its costje corresponding to the 

 original costa;. The costse of P. granulosus are not covered by a subsequent 

 deposit of callous. G-reater diameter of calice, 6.1 mm.; lesser diameter of 

 calice, 6 mm.; height of corallum, 7.2 nnn. 



Locality. — Lowcr layer Woods Bluif, Alabama. 



Geologic occurrence. ^Woods Bluff bcds. 



Type. — From collection of T. II. Aldricli in the United States National 

 Museum. 



'Mon. Brit. Fobs. Corals, Pahcontogr. Soc, 18.50-1854, i). 23, pi. iv, figs. 1. la-lo. 



