CORALS FROM MURRAY, COCOS-KEELING, AND FANNING ISLANDS. 125 



The following is a description of a specimen from Murray Island : 



Corallum with gently convex upper surface. 



Collines obtuse; along the summit there is a furrow to which the outer ends ot the septa 

 extend. Width of intercorallite walls 4.5 to 8 mm. 



Width of series, 13 to 17 mm.; length, 60 to 70 mm.; depth ot valley, 5-5 mm. 



Septa 10 to 1 centimeter, usually alternating in size, thickened in the wall 1 he large 

 septa thick, extend to axes of valleys, upper edges arched or flattish; inner edges slope to 

 bottoms of valleys; smaller septa, thin within valleys, do not reach the axis. I wo or three 

 thick not very prominent teeth on outer edges of large septa; two to five teeth on edges 

 within the valleys, the uppermost the more prominent and sometimes hollow. Maximum 

 lencth of teeth 1.25 mm. Septal faces densely beset with small granulations. 



Columella, flat above, composed of closely twisted trabecule; diameter about 2 by 3 

 mm. Distance apart in valleys about 7 mm. One or two axial septa connect the columellx 



of adjacent polypites. . . ,. , 



Exotheca composed of arched thick-walled vesicles. Endothecal dissepiments about 



1.5 mm. apart. 



Stations at Murray Island—Southeast reef, 1,600 feet from shore, water 10 

 inches deep; and at 1,625 feet from shore, water 14 inches deep at lowest tides; 



hard, rocky bottom. , .,. . • r » r 



It has already been stated that Dana's Mussa nobihs is a renaming of Mean- 

 drina sinuosa Quoy and Gaimard. The Murray Island specimens appear undoubt- 

 edly to belong to the same species as the specimens referred to Symphylha sinuosa 

 by Bedot, but they do not precisely accord with typical specimens. The suite in 

 the U S National Museum is small, comprising only three specimens, from the 

 southern Philippines. The principal difference between these and the Murray 

 Island specimens is in size, the valleys in the typical specimens being wider and 

 deeper, the septal dentations larger, and the intersenal wall sharper. However, 

 around the edges of one Philippine specimen the differences from Murray Island 

 specimen are slight. Width of valleys as small as 11 mm., depth 6 mm. Ihe 

 septal dentations of the former are coarser than those of the latter but of the same 

 pattern and arrangement. Although there are the differences indicated, they are 

 of the kind that may be produced by vegetative causes, and therefore can scarcely 

 be considered of specific value. . 



Svmphyllia indica is closely related to the S. nobihs, notwithstanding its wider 

 and deeper valleys, and apparently is not beyond the range of specific variation. 

 S acuta Quelch is also close. However, until large suites of specimens have been 

 carefully' studied and compared with one another, attempts to determine specific 

 limits and synonymies would be futile. 



Distribution. -MM\ves, Singapore, and Rotuma (Gardiner); Murray Island, 

 Amboina (Bedot); southern Philippines (J. B. Steere); New Mecklenburg (Quoy 

 and Gaimard). Not reported from the Red Sea or east of Rotuma. 



Genus ACANTHASTREA Milne Edwards and Haime. 



1848. Acanlhastrea Milne Edwards and Haime, Acad. Sci., Comptes rend., vol. 27, p. 495- 



Type species: Acanlhastrea spinosa Milne Edwards and Haime, which is the 

 same as Astrcea echinata Dana. 



Acanthastrea echinata (Dana) var. 

 Plate JO, figs. 2, is, and plate 51, fi*. I, Dana', type oUstraa echinata; plate 51, fig. 2, var. from Murray Island. 

 ,846 Astrcea echinata Dana, U. S. Expl. Exped., Zooph., p. 229, plate 12, figs. 1, la-lb. 

 ,857. Acanlhastrea ? echinata Milne Edwards and Haime Hist. nat. Coral!., vol. 2, p 504- 



Favia htrsuta Matthai, Trans. Linn. Soc. London, 2d ser., Zool., vol. .7, P- 100, plate 24, figs. 7, 8. 



