272 DR. J. W. GREGORY ON THE PALEONTOLOGY [Aug. 1895, 



Species 2. Orbicella acropora (Linnaeus), 1767. 



Synonymy : — 



Madrepora acropora, Linnaeus, 1767, ' Syst. Nat.' ed. xii. p. 1276 ; Gmelin, 1790. 

 ibid, ed.xiii. p. 3767 ; Esper, 1794,'Pflanzenth.'Fortsetz. Bd.i. pp. 21-23, pi. Madrep. 

 xxxviii. 



Heliastrcea acropora, M. -Edwards & Haime, 1857, ' Hist. Nat. Cor.' t. ii. p. 477 ; 

 Duchassaing & Michelotti, 1861, ' Mem. Cor. Ant.' Mem. R. Accad. Sci. Torino, ser. 2, 

 t. xix. p. 179 ; iid. 1866, ' Suppl. etc' ibid. ser. 2, t. xxiii. p. 352 ; Duchassaing, 1870, 

 ' Rev. Zooph. Ant.' p. 30. 



Madrepora annularis, Ellis & Solander, 1786, ' Nat. Hist. Zooph.' p. 169, pi. liii. 

 figs. 1-2. 



Astrcea annularis, Lamarck, 1816, ' Hist. Nat. Anim. s. Vert.' t. ii. p. 259 ; id. 1816, 

 'Encvcl. Meth. Atlas,' pi. 486. figs. 1-2; Lamouroux, 1821, 'Expos. Meth.' p. 58, 

 pi. liii. figs. 1-2 ; id. 1824, Encvcl. Meth., ' Zooph.' p. 131 ; Lamarck, 1836, ' Hist. Nat.' 

 ed. 2, t. ii. p. 405 ; Schomburgk, 1847, ' Hist. Barbados,' p. 562 ; M.-Edwards & Haime, 

 1849, ' Monogr. Astr.' Ann. Sci. Nat. Zool. ser. 3, t. xii. p. 104 



Astrcea (Tubastrcea) annularis, Blainville, 1830, Diet. Sci. Nat. t. lx. p. 334 ; id. 

 1834, ' Man. Act,' p. 368. 



Explanaria annularis, Ehrenberg, 1834, ' Cor. roth. Meer.' Abh. k. Akad. Wiss. 

 Berlin, 1832, p. 308. 



Orbicella annularis, Dana, 1848. 'Zooph. Explor. Exped. Wilkes, "vol. viii. p. 214. 

 pi. x. fig. 6 ; Verrill, 1864, ' List of Corals,' Bull. Mus. Comp. Zool. vol. i. p. 48 ; Pour- 

 tales, 1871, ' Deep-Sea Corals,' 111. Cat. Mus. Comp. Zool. no. iv. p. 77 ; Lindstrom, 

 1877, 'Contrib. Act. Atl.' Handl. k. Svensk. Vet,- Akad. Bd. xiv. no. 6, p. 23 ; Pour- 

 tales, 1880, ' Plor. Reefs,' Mem. Mus. Cornp. Zool. vol. vii. no. 1, pi. iv ; A. Agassiz, 

 1890, ' Rate of Growth,' Bull. Mus. Comp. Zool. vol. xx. p. 61, pis. i., ii. ; Heilprin. 

 1890, 'Cor. W. Gulf Mexico,' Proc. Acad. Nat. Sci. Phil. 1890, p. 305. 



Heliastrcea annularis, M.-Edwards & Haime, 1857, ' Hist. Nat. Cor.' t. ii. p. 473 : 

 Duchassaing & Michelotti, 1861, 'Mem. Cor. Ant.' p. 352; iid. 1866, ' Suppl. etc' 

 p. 179 ; Duchassaing, 1870, ' Rev. Zooph. Ant.' p. 30; Ortmann, 1888, 'Stud. Syst. 

 Verbr. Steinkor.' Zool. Jahrb. Bd. iii. Syst. p. 174 ; id. 1889, ' Steinkor. Cevlons,' ibid. 

 Bd. iv. Syst. p. 529 ; id. 1890, ' Morph. Skel. Steinkor.' Zeitschr. Wiss. Zool. Bd. 1. 

 p. 307. 



Madrepora faveolata , Ellis & Solander, 1786, 'Nat. Hist. Zooph.' p. 166, pi. liii. 

 figs. 5-6 ; Gmelin, 1790, ' Syst. Nat.' ed. xiii. p. 3769. 



Orbicella Hyades, Dana, 1848, ' Zooph. Explor. Exped. Wilkes,' p. 212, pi. x. 

 fig. 15. 



Heliastrcea ? Hyades, M.-Edwards & Haime, 1857, ' Hist. Nat. Cor.' t. ii. p. 478. 



Solenastrcea Hyades, Duchassaing & Michelotti, 1861, ' Mem. Cor. Ant.' p. 353 : 

 iid. 1866, ' Suppl.' etc' p. 179 ; Duchassaing, 1870, ' Rev. Zooph. Ant.' p. 30. 



Heliastrcea abdita, Duchassaing & Michelotti, 1861, op. supra cit. p. 352; iid. 

 1866, op. supra cit. p. 179 ; Duchassaing, 1870, op. supi-a cit. p. 30. 



Heliastrcea rotulosa, Duchassaing & Michelotti, 1861, op. supra cit. p. 352; iid. 

 1866, op. supra cit. p. 179 ; Duchassainoc, 1870, op. supra cit. p. 30. 



Astrcea barbadensis , Duncan, 1863, ' Foss. Cor. W. Ind.' pt. i. , Quart. Journ. Geol. 

 Soc vol. xix. pp. 421, 444-445, pi. xv. fig. 6 a, b. 



Heliastrcea barbadensis, Diichassaing & Michelotti, 1866, 'Mem. Cor. Ant.' 

 p. 180; Duncan, 1868, ' Foss. Cor. W. Ind.' pt, iv., Quart. Journ. Geol. Sac. vol. 

 xxiv. p. 12 ; Duchassaing, 1870, ' Rev. Zooph. Ant.' p. 30. 



Heliastrcea altissima, Duncan, 1868, ' Foss. Cor. W. Ind.' pt. iv., vol. xxiv. 

 pp. 12-13, pi. ii. fig. 3. 



Distribution. Recent: West Indies, Florida, Yucatan, ? Samoa (fide Ortmann). 

 Fossil : Barbados : Low-level Reefs near Bridgetown (Franks Coll.) ; Ceres (Jukes- 

 Browne Coll.); High-level Reefs, Castle Grant, 1050 feet (Jukes-Browne Coll.); 

 summit of Mt. Misery, 1053 feet (Col. Feilden Coll.). Trinidad, St. Croix (Geol. Soc. 

 Coll.) ; Antigua, Marl. 



Notes on Synonymy. — The main point in the synonymy of this 

 species is the determination as to whether 0. annularis should 

 be kept distinct. At first I thought that this could be done, 

 owing to the fact that in 0. annularis the costse are subequal, 

 though the septa of the third cycle are very small. In 0. acropora, 

 on the other hand, there is a rudimentary costa between those cor- 

 responding to the third cycle of septa ; these rudimentary costas do 

 not themselves correspond to septa. This point seemed a satis- 



