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



Notes on Synonymy. — As this is the type-species of its genus, it is 

 convenient to consider in connexion with it the correct name of the 

 genus — a subject which has given rise to much difference of opinion. 

 Lamarck, in 1801, used the term Astrcea for two species, rotulosa 

 and galaxea, but does not definitely name either as the type. Fischer 

 de Waldheim came next ; he quoted Lamarck's diagnosis, with only 

 unimportant verbal additions. He does not mention rotulosa, but 

 includes radians in Astrcea. The diagnosis used both by him and 

 Lamarck certainly applies better to radians than to rotidosa. 



The genus was first properly subdivided by Oken in 1817. He 

 restricted Astrcea to galaxea, and proposed the genus Favia for the 

 other. According to the rule — that when an author includes two or 

 more species in a genus which is subsequently dismembered, and does 

 not definitely choose one species as his type, the author who subdivides 

 the genus has the right to select any species as the type — M.-Edwards 

 & Haime were quite right in taking radians as the type of Astrcea. 

 This leads, however, to the unfortunate position that Astrcea is 

 not one of the Astraean corals. To obviate this difficulty, Blainville 

 renamed Astrcea, Siderastrcea. Duncan follows the same course, by 

 which Astrcea would fall out of use. Quelch, however, goes back 

 beyond Oken, uses Astrcea for the roUdosa-growp of species, makes 

 Favia a synonym of Astrcea, and accepts Siderastrcea for the radians- 

 group. 



But this course is opposed to the rule already quoted. The 

 only chance of escape from the solution adopted by M.-Edwards & 

 Haime is a prior use of the name Astrcea. Before Lamarck, Gmelin 

 used it for Madrepora astroites (p. 3767), but his diagnosis is so 

 uncertain that one cannot base anything upon it. Brown 1 used 

 Astrcea for a coral, but his description is so ill-defined that it is im- 

 possible to recognize what was intended. Bolten used the term for 

 a mollusc in 1798 ; but it is not used in conchology, and I cannot 

 find what he meant by it. We seem, tberefore, bound to follow 

 the course taken by Milne-Edwards & Haime. 



Species 2. Astrea siderea (Ell. & Sol.), 1786. 



Synonymy : — 



Madrepora siderea, Ellis & Solander, 1786, 'Nat. Hist. Zooph.' p. 168, pi. xlix. 

 tig. 2 ; Gmelin, 1790, ' Syst. Nat.' ed. xiii. p. 3765. 



Astrcea siderea, Lamarck, 1816, ' Hist. Nat. Anim. s. Vert.' t. ii. p. 267 ; Lesueur, 

 1820, ' Polyp. Lam.' Mem. Mus. Hist. Nat. t. vi. p. 286, pi. xvi. tig. 14 ; Lamouroux, 

 1821, ' Exp. Meth.' p. 60, pi. xlix. fig. 2 ; id. 1824, Encycl. Meth., ' Zooph.' p. 126 ; 

 Lamarck, 1836, ' Hist, Nat. etc' ed. 2, t. ii. p. 417; M.-Edwards & Haime, 1857, 

 ' Hist. Nat. Cor.' t. ii. p. 509; Duchassaing & Michelotti, 1861, ' Mem. Cor. Ant.' 

 Mem. R. Accad. Sci. Tor. ser. 2, t. xix. p. 354; iid. 1866, ' Suppl. etc' ibid. ser. 2, 

 t. xxiii. p. 183 ; Duchassaing, 1870, ' Rev. Zooph. Ant.' p. 31. 



Astrcea {Siderastrcea) siderea, Blainville, 1830, ' Zooph.' Diet. Sci. Nat. t. lx. 

 p. 335 ; id. 1834, 'Man. Act.' p. 370. 



Siderastrcea siderea, M.-Edwards & Haime, 1849, ' Monogr. Astr.' Ann. Sci. Nat,, 

 Zool. ser. 3, t. xii. p. 141 ; iid. 1851, ' Polyp. Paleoz.' Arch. Mus. Hist. Nat, t. v. p. 105 ; 

 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. 81. 



1 Patrick Brown, ' Civil & Natural History of Jamaica,' 1789, p. 392. 



