24 PROF. p. MARTIN DUNCAN's REYISION OF THE 



G-enus Paracyathus, Milne-Edwards ^ Jules Saime, Hist. Nat. 

 des Gorall. vol. ii. p. 52 (1857). 



Corallum simple, subturbinate or variable in shape, fixed with 

 a broad base ; calice circular or elliptical, open. Columella fas- 

 ciculate, papillary at the surface, depressed centrally, raised where 

 its outer papillae are with difficulty distinguished from the pali. 

 These are numerous, and before all the cycles of septa except 

 the last, and the youngest are the largest, often bilobed and pro- 

 jecting, often granular. Septa close, subequal, not very exsert, 

 granulated. Costse indistinct or fairly developed. Eudimentary 

 epitheca rarely present. 



Distribution. — Fossil. Eocene : Europe, England. Miocene, 

 Pliocene : Europe. — Recent. Mediterranean, Indian Ocean, 

 Pacific, California (Pearl Islands), Caribbean Sea, N". Atlantic, 

 Josephine Bank. 



The genus Platycyathus, E. de From. Pal. Prang., Terr, cret., 

 is a discoid TrochocyatJius, and is therefore absorbed. 



G-enus Heteroctathtjs, Milne-Edwards Sf Jules Saime, Hist. 

 Nat. des Gorall. vol. ii. p. 51 (1857). 



Corallum simple, the base growing more or less entirely over a 

 small shell upon which it is fixed. Calice as large as the base, 

 subcircular. Columella feebly developed, and composed of 

 slender points. Septa very exsert, thick, and unequal, in four 

 cycles with an incomplete fifth. The septa of the last cycle more 

 developed than the penultimate septa ; and they diverge slightly 

 from their neighbours of the higher orders. Pali very slender, 

 denticulate, before all the septa. "Wall with distinct equal costse. 

 No epitheca. 



Distribution. — Mecent. Philippine, Corean, and East- African 

 seas. 



Semper states that there are fossil species (Die natiir. Existenz. 

 der Thiere, pt. ii. p. 167, 1880). 



The figure given by the authors of the genus indicates that a 

 Sipunculid worm lives in the base of the coral, communicating 

 with the outside by means of small openings. Some forms grow 

 upon dead OenYAmra-shells which are occupied by a Sipunculid. 



Genus Cartophtllia, Lamar ch, Syst. Anim. sans Verteb. 

 1801, p. 370, amended. 



Corallum simple, with a broad or narrow adherent base, or 



