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



Leptastrea purpurea (Dana). 



Plate 30, figures I, la, Dana's type of Astrcea purpurea; figure 2, specimen from Murray Island; figures 3, 3a, speci- 

 men from Cocos-Keeling Islands. Also plate 17, figure }}, of Dr. Mayer's article. 



1846. Astrcea purpurea Dana, U. S. Expl. Exped., Zooph., p. 239, plate 12, figs. 10, ioa-ioc. 



1846. Astrcea pulchra Dana, U. S. Expl. Exped., Zooph., p. 240, plate 12, figs. 11, na-nf. 



1849. Leptastrea ehrenbergiana Milne Edwards and Haime, Ann. Sci. nat., 3d ser., Zool., vol. 12, p. 120. 



1857. Leptastrea ehrenbergana Milne Edwards and Haime, Hist. nat. Corall., vol. 2, p. 41)4, plate D 7, fig. 4. 



1857. Prionastrcea purpurea Milne Edwards and Haime, Hist. nat. Corall., vol. 2, p. 524. 



1867. Leplaslrcea stellulata Verrill, Proc. Essex Inst., vol. 5, p. 36. 



1872. Leptastrea purpurea Verrill, in Dana's Corals and Coral Islands, p. 381. 



1907. Favia hawaiiensis Vaughan, U. S. Nat. Mus. Bull. 59, p. 10;, plate 26, figs. 3, 33. 



1914. Leptastrea ehrenbergana Matthai, Trans. Linn. Soc. London, 2d ser., Zool., vol. 17, p. 68, plate 17, 



figs- 5 - 7; p' ate l8 > figs- 2 ar >d 7; p' ate '9» fie s - 3 ar "' 4i P' ate 34. fig- 8 



The following description is based on Dana's type of Astrcea purpurea, which 

 is preserved in the U. S. National Museum, No. 75: 



Corallum massive, upper surface with both curved and flattish areas, transverse profile 

 in most directions an undulating line. Greatest diameter of specimen 85 mm.; thickness, 

 38 mm. 



Calices polygonal, separated by a narrow intercorallite groove at which the outer ends 

 of the septa terminate. Range in diameter from 2 mm. to 9 mm., the large calices, which 

 are usually deformed, being most commonly on the tops of undulations; 4.5 to 5 mm. is a 

 common diameter for fully developed calices. Depth of medium-sized calices about 2 mm.; 

 of the large calices, usually 3 mm. 



The walls, including the thecal thickenings of the septa, range from 0.5 mm. to a little 

 more than I mm. in thickness. The outer septal ends form subequal costae, are swollen in 

 the theca, and frequently are hollow. In the calices, described below, in which there are 

 64 septa, 8 septa are hollow in or near the theca. This condition is probably pathologic. 

 The septal margins over the theca may be exsert up to 0.75 mm., but are usually less. 



The septa vary in number according to the size of the calices. A small calice, 2 mm. 

 in diameter, has 26 septa, alternately larger and smaller, 12 of the larger reaching the colu- 

 mella tangle. The 6 primary septa may be distinguished, but are scarcely more prominent 

 than the secondary; the tertiaries even in the small calices show tendency toward fusion to 

 the sides of the secondaries. In one half system the tertiaries have fused to the neighbor- 

 ing secondary and two distinct but small quaternary septa are present. A medium-sized 

 calice, 5 mm. in diameter, has 36 septa, alternately larger and smaller. The primaries 

 and secondaries in this calice are scarcely distinguishable and reach the columella tangle; 

 the tertiaries usually fuse to the sides of the secondaries about half-way between the wall and 

 columella where no quaternaries are present, but near the columella where quaternaries are 

 present; the quaternaries have free inner edges or are fused to the sides of the included tertia- 

 ries. A large calice, 8 by 9 mm. in diameter, has 64 septa. The 6 primaries are somewhat 

 wider and thicker than the secondaries, and are therefore distinguishable from the latter. 

 Both of these cycles and occasionally a tertiary reach the columella. The number of septa 

 indicates 4 complete cycles and i6quinaries. The members of the cycles above the secon- 

 daries group around the secondaries in each system, the tertiaries fusing to the sides of the 

 secondaries near the columella, the quaternaries fusing to the tertiaries, and quinaries fusing 

 to the quaternaries, unless decidedly small. 



The calicular fossae are usually open, rather hopper-shaped, since, except a curve of the 

 larger septa near the wall, the septal margins slope to near the columella — the inner edges of 

 the larger septa are not subvertical but slope downward and inward. The upper margins of the 

 septa over the theca are obscurely dentate, subentire, but the presence of divergent trabecules may 

 be recognized. As the columella is approached the dentations become more pronounced, so 

 that just above the columella there is a crown of inwardly projecting, upward slanting, rather 

 long, slender teeth, usually on all the long septa, but sometimes lobes composed of fused teeth 

 may be present on some of the primaries. The septal faces are beset with relatively coarse, conical 



granulations. 



The columella is rather weakly developed; it is really a columella tangle, composed 

 of septal spines and fused septal ends. Its diameter is about one-fifth that of the calice. 



Both thickish and thin endothecal dissepiments are present; there are stout exothecal 

 cross-connections between the walls of adjacent corallites. 



Asexual reproduction by interstitial budding. 



