GEOLOGY AND PALEONTOLOGY OP THE CANAL ZONE. 439 



2. SIDERASTREA RADIANS (Pallas). 



Plate 114, fig. 1. 



1766. Madrepora radians Pallas, Elench. Zooph., p. 322. 



1767. Madrepora astroites Linnaeus, Syst. Nat., ed. 12, p. 1276 (not Pallas, 



1766) . 

 1786. Madrepora galaxea Ellis and Solander, Nat. Hist. Zooph., p. 168, 



pi. 48, fig. 7. 

 1801. Astrea galaxea Lamarck, Syst. Anim. s. Vert., p. 371. 

 1815. Astraea radians sen astroites Oken, Lehrb. Natufgesch., Th. 3, Abth 1, 



p. 65. 

 1830. Astrea (Siderastrea) galaxea De Blainville, Diet. Sci. "nat., vol. 60, p. 



335. 

 1834. Astraea astroites Ehrenberg, Cor. Roth. Meer., p. 95 (of separate). 



(Not Explanaria galaxea Ehrenberg= Cyphastraea savignyi Milne Edwards 



and Haime.) 

 1846. Siderina galaxea Dana, U. S. Expl. Exped. Zooph., p. 218, pi. 10, 



figs. 12. 12b, 12c (not figs. 12«, 12d). 

 1880. Siderastraea galaxea Pourtales, Mus. Comp. Zool. Mem., vol: 7, pt. 1, 



pi. 11, figs. 14-31; pi. 15, figs. 1-12, 

 1895. Astraea radians Gregory, Geol. Soc. Lond. Quart. Journ., vol. 51, p. 277. 

 1901. Siderastrea radians Vaughan, Geolog. Reichs. Mus. Leiden Samml., ser. 2, 

 vol. 2, p. 61. 



1901. Siderastrea radians Vaughan, U. S. Fish Com. Bull, for 1900, vol. 2, p. 



309, pi. 15, pi. 16, fig. 2. 



1902. Siderastraea radians Verrill, Conn. Acad. Arts and Sci. Trans., vol. 11, p. 



153. pi. 30, fig. 1. 

 1904. Siderastrea radians Duerden, Carnegie Inst. Washington Pub. No. 20, pp. 

 1-130, 11 plates. 



1915. Siderastrea radians Vaughan, Washington Acad. Sci. Journ., vol. 5, p. 597. 



1916. Siderastrea radians Vaughan, Nat. Acad. Sci. Proc, vol. 2, pp. 95 et passim. 

 1916. Siderastrea radians Vaughan, Carnegie Inst. Washington Yearbook No. 14, 



p. 228. 



This is one of the best known species of Antillean corals. Its 

 most important characters may be summarized as follows: Calices 

 more or less deformed or subhexagonal; diameter from 2 to 4 mm.; 

 septa in 3 complete cycles; fourth cycle normally incomplete. Outer 

 part of septal margins flattened above, inner part falls steeply, 

 almost perpendicularly, to the bottom of the columellar fossa; septal 

 dentations relatively coarse, 12 to 14 on long septa. Columella 

 usually composed of two or three solidly fused papillae. All of these 

 characters are shown on plate 35, figure 1. 



Locality and geologic occurrence. — Canal Zone, stations 5850 and 

 6039, Pleistocene, Mount Hope, collected by D. F. MacDonald. 

 Common on the living and Pleistocene reefs and reef flats of eastern 

 Central America, the West Indies, and Florida; on the living reefs 

 and reef flats of the Bermudas. 

 37149— 19— Bull. 103 17 



