280 DR. J. W. GREGORY ON THE PALEONTOLOGY [Aug. 1 895, 



N on Pavonia cristata, Lamarck, 1816, et auet. ; ? Deslongchamps, 1824, Encycl. 

 M6th. p. 604. 



Agaricia cristata, Duchassaing, 1847, ' Const, geol. Guad.' Bull. Soc. geol. France, 

 ser. 2, t. iv. p. 1097. 



? Agaricia arthrophylla, Horn, 1860, Proc. Acad. Nat. Sci. Phil. 1860, p. 435. 



Madrepora undata, Ellis & Solander, 1786, ' Nat. Hist. Zooph.' p. 157, pi. xl. ; Esper, 

 1795, ' Pflanzenth.' Fortsefcz. Bd. i. p. 98, pi. Madr. lxxviii. 



Agaricia undata, Lamarck, 1801, ' Syst. Anim. s. Vert.' p. 373 ; id. 1816, ' Hist. 

 Nat. Anim. s. Vert.' t. ii. p. 242 ; Lamouroux, 1821, ' Exp. Meth.' p. 54, pi. xl. ; id. 

 1824, Encycl. Meth., ' Zooph.' p. 13 ; Blainville, 1830, ' Zooph.' Diet. Sci. Nat. t. lx. 

 p. 326 ; id. 1834, 'Man. Act.' p. 361 ; Lamarck, 1836, ' Hist. Nat. etc' ed. 2, t. ii. 

 p. 381 ; Dana, 1848, 'Zooph. Explor. Exped. Wilkes,' vol. viii. p. 336 ; Duchassaing, 

 1850, ' Anim. rad. Ant.' p. 17 ; M.-Edwards & Haime, 1851, ' Monogr. Fong.' Ann. 

 Sci. Nat. Zool. s6r. 3, t. xv. p. 129; iid. 1851, 'Polyp. Paleoz.' Arch. Mus. Hist. 

 Nat. t. v. p. 129 ; iid. 1860, ' Hist. Nat. Cor.' t. iii. p. 83 ; Duchassaing & Michelotti 

 1861, ' Mem. Cor. Ant.' Mem. R. Accad. Sci. Tor. ser. 2, t. six. p. 357. 



Agaricia undata, var., Duncan, 1863, ' Foss. Cor. W. hid.' pt. i., Quart. Journ. Geol. 

 Soc. vol. xix. p. 437. 



Non Agaricia undata, Duncan, 1868, op. cit. pt. iv., ibid. vol. xxi. p. 12. 



Agaricia undata, Duchassaing, 1870, 'Rev. Zooph. Ant.' p. 31. 



TJndaria undata, Oken, 1815, ' Lehrb. Naturg.' Zool. Bd. i. p. 69. 



Pavonia undata, Blainville, 1830, ' Zooph.' Diet. Sci. Nat. t. lx. p. 331 ; id. 1834, 

 op. cit. p. 365 ; Duchassaing, 1847, ' Const, geol. Guad.' Bull. Soc. geol. France, 

 ser. 2, t. iv. p. 1097. 



Agaricia purpurea, Lesueur, 1820, ' Polyp. Lam.' Mem. Mus. Hist. Nat. t. vi. p. 276, 

 pi. xv. fig. 3 ; Verrill, 1864, ' List of Corals,' Bull. Mus. Comp. Zool. vol. i. p. 55 ; 

 Pourtales, 1871, ' Deep-Sea Corals,' 111. Cat. Mus. Comp. Zool. no. iv. p. 82 ; Quelch, 

 1886, ' Reef Corals,' Zool. ' Chalk' Exped. pt. xlvi. p. 12. 



Mycedia purpurea, Dana, 1848, ' Zooph. Explor. Exped. Wilkes,' vol. viii. p. 340. 



Mycedium pur pur eum, Duchassaing & Michelotti, 1861, ' Mem. Cor. Ant.' p. 357. 



Mycedia gibbosa, Dana, 1848, ' Zooph. Explor. Exped. Wilkes,' p. 341. 



Mycedium gibbosum, Duchassaing & Michelotti, 1861, op. supra cit. p. 357. 



Agaricia 1 gibbosa, M. -Edwards & Haime, 1860, ' Hist. Nat. Cor.' t. iii. p. 84. 



Mycedium Lessoni, Duchassaing & Michelotti, 1861, op. cit. p. 357 ; iid. 1866, ' Suppl. 

 etc' Mem. R. Accad. Sci. Tor. ser. 2, t. xxiii. p. 186 ; Duchassaing, 1870, ' Rev. Zooph. 

 Ant.' p. 31. 



Mycedium vesparium, Duchassaing & Michelotti, 1861, op. supra cit. p. 357 ; iid. 

 1866, op. supra cit. p. 186 ; Duchassaing, 1870, op. supra cit. p. 31. 



Agaricia vesparium, Quelch, 1886, ' Reef Corals,' Zool. ' Chalk' Exped. pt. xlvi. 

 p. 12. 



Distribution. Recent : West Indies ; North America and Bermuda ; South 

 America. Fossil : Barbados : Low-level Reefs. San Domingo : Nivaje' Shale. 

 Guadeloupe : Older or White Limestone. 



Notes on Synonymy. — The M. Lessoni is a specimen with crowded 

 collines. The decision to merge the species A. undata with A. aga- 

 ricites seems at first of very doubtful value. The two types of calicular 

 structure appear very distinct. A specimen from the Franks Collec- 

 tion (B.M. E 2482) has, however, both types on different sides 

 of the coral ; the two areas are of corresponding age and appear to 

 have grown under the same conditions. The striking difference in 

 appearance is therefore remarkable. PI. XI. fig. 7 a shows a part 

 of the coral with the characters of the typical Agaricia agaricites, 

 and fig. 7 b shows a part which, if found separately, would have been 

 referred to A. undata. This specimen not only unites the two 

 species, but shows that the distinctions between the two genera 

 Agaricia and Mycedium are valueless ; for the one side of the 

 specimen is an Agaricia and the other a Mycedium. 



Species 2. Agaricia elephantotus (Pallas), 1766. 



Synonymy : — 



Madrepora elephantotus, Pallas, 1766, ' Elench. Zooph.' p. 290 ; Esper, 1789, 

 , Pflanzenth.' Bd. i. pp. 126-128, pi. Madr. xviii.; Gmelin, 1790, 'Syst. Nat.' ed. xiii. 

 p. 3759. 



