438 SYSTEMATIC TALEOXTOLOGY 



Occurrence. — Calvert Formation. Plum Point. 

 Collection. — U. S. National Museum. 



Class ANTHOZOA. 



Order ACTINl/E. 



Suborder SCLEACTINI/E. 



Family CYATHOPHYLLID/E Verrill. 



Genus PARACYATHUS Milne-Edwards and Haime. 



Paracyathus vaughani Gane. 

 Plate CXXII, Figs. 1, 2, 3. 



Paracyathus vaughani Gane, 1895, Johns Hopkins Univ. Giro., vol. xv, No. 121, p. 9. 

 Paracyathua vaughani Gane, 1900, Proc. U. S. Nat. Museum, vol. xxii, pi. xv, figs. 

 4-6. 



Description. — Corallum small, broad and low, with the ealice about 

 the same diameter as the base, above which the wall is somewhat con- 

 stricted. Wall thin, costulate to its base. Costse low, unequal, iiuely 

 granular, more prominent near the calicular margin where they are con- 

 siderably thicker than their corresponding septa. Calice circular in the 

 young, slightly oval in the adult individual; fossa broad, moderately 

 deep. Septa in six systems of five cycles, lacking part of the sixth order 

 of the last cycle ; in individuals of medium size only four cycles are pres- 

 ent. Primaries and secondaries subequal, thick and stout, with summits 

 more broadly rounded and more strongly exsert than those of the re- 

 maining thin and slender septa; sides coarsely granulated, upper mar- 

 gins of all septa entire, the inner portion of the margins of the higher 

 cycles crenately dentate. Pali granular, consisting of several small lobes, 

 becoming confused with the papillae of the columella, present before all 

 the septa but those of the last cycle, excepting in the most mature forms, 

 where they may be lacking before a part of the fourth as well as before all 

 of the fifth cycle of septa. Columella papillose, well developed. 



In polishing down the base of the coral, the rings marking the exist- 

 ence of previous outer walls are clearly seen. In one specimen no less 

 than eight appear, showing the growth of the coral and its relation to 

 the development of its septa. 



