DESCRIPTIONS OF SPECIES. 109 



so the granules often fuse across the interseptal loculi. There are some 

 projections extending inward from the wall, and the granules are elongated 

 in curves parallel to septal margin. The latter is true to a less degree in 



/'. alternatus. 



This species resembles Paracyathus crtr?/op%/?MS (Lamarck) ^ quite closely 

 in its form and in the character of the costa;. A study of specimens of the 

 latter in the British Museum (Natural History) showed it to be a decidedly 

 Larger species, and its calice is deeper. 



Paracyathus rugosus sp. nov. 



PI. VIII, figs. 21 to 21b. 



Only one specimen of this species has come under my observation, 

 and it can be best characterized by a differential description. 



Looked at superficially, the species resembles P. heUus; the first diff'er- 

 ence is that the corallum of P. rugosus enlarges more rapidly in diameter as 

 it increases in height. The costse of P. rugosus are composed entirely of a 

 series of subtriangular plates whose upper angles project a little. The 

 costffi are very rough, and if the end of the finger is drawn along them 

 from the calicular margin toward the place of attachment, the projecting 

 points will catch in it. The costa? correspond to all cycles of septa, and 

 there is no alternation in size. Septa in three cycles. Pali as usual in 

 the genus. ' Diameter of calice, 4 mm.; height of corallum, 9 ram. 



Locality.— Lower bed. Woods Bluft", Alabama. 



Geologic occurrence. Woods Bluflf bcds. 



Type.—From collection of T. H. Aldrich in the United States National 



Museum. 



Paracyathus cylindrious sp. nov. 



PI. IX, figs. 1 to lb. 



This species is extremely close to P. hellus. In shape its base is pro- 

 portionately broader. The principal difi'erence between the two species is 

 in the character of their costse. In P. hdlus the intercostal fun-ows are 

 verynarrow; they are not so wide as the costa;; in P. cyUndrkus the costse 

 are not so prominent as in P. hellus, and'the intercostal furrows are much 

 wider. The costje are low, acute, equal in size, granulate; there are gran- 



■ Milne- Edwards and Haime, Mod. Brit. Foss. Corals, Palajontogr. Soc, 1850-1854, p. 24, pi. iv, fig. 

 2, 2a-2c. 



