258 



DR. J. W. GREGORY ON" THE PALAEONTOLOGY [Aug. 1 895, 



Order MADREPORARIA. Suborder APOROSA. 



Eamily OCTTLINID^]. 



Genus Madracis, M.-Ed. & H., 1849. 



Syn. Reussia, Ducli. & Mich. ; Pentalophora, Sav. Kent ; Axolielia, M.-Ed. & H. 



Species Madracis decactis (Lyman). 



Synonymy : — 



Astrcea decactis, Lyman, 1859, ' New Sp. Coral.' Proc. Bost. Soc. Nat. Hist, 

 vol. vi. pp. 260-263. 



Madracis decactis, Verrill, 1864, 'List of Corals sent etc' Bull. Mus. Comp. 

 Zool. vol. i. p. 45 ; Pourtales, 1871, 'Deep-Sea Corals,' 111. Cat. Mus. Comp. Zool. 

 no. iv. pp. 28 & 67 ; id. 1874, ' Hassler Corals,' ibid. no. viii. p. 41 ; Lindstrom, 1877, 

 'Actin. Atl.' Handl. k. Svensk. Vet.-Akad. Bd. xiv. no. 6, p. 15; Quelch, 1886, 

 ' Reef Corals,' Zool. ' Chall.' Exp. pt. xlvi. p. 53. 



Reussia lamellosa, Duchassaing & M\chelotti, 1861, ' Mem. Cor. Ant.' Mem. R. 

 Accad. Sci. Tor. ser. 2, t. xix. p. 339, pi. ix. fig. 8; iid. 1866, 'Suppl. Cor. Ant.' 

 ibid. ser. 2, t. xxiii. p. 164; Duchassaing, 1870, 'Rev. Zooph. Ant.' p. 26. 



Stephanocoenia dendroidea, non M.-Edw. & H., Duncan, 1863, ' W. Ind. Cor.' pt. i. 

 Quart. Journ. Geol. Soc. vol. xix. p. 432. 



? Stylophora minuta, Duncan, 1868, ' W. Ind. Cor.' pt. iv. ibid. vol. xxiv. p. 14. 



Distribution. Recent : St. Thomas, Barbados, Florida (6-17 faths.), Bermuda. 

 Fossil : Pleistocene, Bermuda (Coll. Geol. Soc.) ; Barbados : Low-level Reefs 

 (B.M. Coll. Presented by G. P. Pranks, Esq.) ; San Domingo : Nivaje & Cerro Gordo 

 Shales (Coll. Geol. Soc). 



Notes on the Species. — The genus is said by Duncan to bave 

 no costas, while both he and Milne-Edwards & Haime in their 

 original diagnosis state 



Eig. 1. — Section of Madracis 

 decactis (Lym.). (xl2 diam.) 



that the septa are all of 

 uniform size. This was 

 one of its differences from 

 the nearly allied Stylo- 

 phora. Some sections, 

 however, cut from the 

 specimens from Barbados, 

 show that a rudimentary 

 set of septa and also costse 

 may be sometimes present 

 (see fig. 1). Quelch in- 

 cludes Duchassaing & 

 Michelotti's species Stylo- 

 phora incrustans as a 

 synonym of this ; but 

 the figure is useless, and 

 I did not see the type 

 at Turin. The type of 

 Duncan's S. minuta was 

 lost, and so the value 

 of this species cannot be 

 determined ; the two spe- 

 cimens identified by that 



author as Stephanoccenia dendroidea are both in the Society's 

 Museum; they certainly belong to Madracis, and appear to be 

 only a form of M . decactis, which grows out into low, cjdindrical, 

 massive branches. 



To show rudimentary septum (S). 



