146 PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



The notes suggest that the list of species of Astreopora from Australia should 

 be A. myriophthalma (Lamarck), A. ocellata Bernard, A. punctifera (Lamarck), and 

 A. profunda Verrill. 



Astreopora myriophthalma (Lamarck). 



Plate 60, figures 5, 5a, specimen from Cocos-Keeling Islands. 



1879. Astreopora myriophthalma Klunzinger, Korall. Roth. Meet., pt. 2, p. 52, plate 5, fig. 31. 



1896. /Islraopora myriophthalma Bernard, Cat. Gen. Astreopora, p. 87, plates 25, 26; plate 33, fig. 9. 



1896. Astraopora ehrenbcrgii Bernard, Cat. Gen. Astrieopora, p. 92, plate 33, fig. 15. 



The following is a description of a specimen of Astreopora myriophthalma from 

 Cocos-KeeHng Lslands: 



Cornllum pulvinate; horizontal diameter about 85 mm.; thickness, 51 mm. 



Calices, diameter of largest 2.25 mm., usual range from 1.5 to 2 mm., 1.5 mm. a frequent 

 measure, average size therefore small. Distance apart 2 to 4 mm. Margins elevated, 

 often 2 mm. or more, up to at least 3 mm., usually of fairly uniform height. The walls are 

 perforate membranes. Outside the walls the corallites are swollen toward the base of the 

 projecting part, the slope from one calice meeting that from its neighbor. Costae thin, prom- 

 inent, correspond to septa of the first and second cycles and an occasional tertiary. They 

 are jaggedly dentate, the dentations, which end in spiniform teeth, increase in height from 

 the calicular margin downward. Small calices, down to I mm. in diameter, between the 

 larger. 



Septa, primaries narrow above, wide below, where their edges often meet and fuse by 

 spiniform processes, but never form a well-developed columella; secondaries usually present 

 but always narrow; very rarely may a rudimentary tertiary be distinguished. 



Tabulae irregularly developed, thin, I to 3 mm. apart. 



Coenenchyma forms fairly continuous but perforate platforms; successive floors fairly 

 definite in longitudinal sections; over its surface tall, hirsute spinules, which usually end in 

 single, occasionally in double, rarely in fimbriate points. 



Habitat, etc., Cocos Keeling Islands. — "Barrier pools; color of living colonies 

 yellow or purple" (F. Wood Jones). 



Another specimen has a denser corallum, the costse and coenenchyma! spines 

 are lower, and the primary septa do not meet in the axis, but the scheme of the 

 relations of the structural elements is the same as in the specimen described in detail. 



Bernard described two species of Astreopora, in which there are prominent, 

 roughlv dentate costse around the calices, viz, A. myriophthalma (Lamarck) and 

 A. hirsiita Bernard, and apparently A. ehrenbergii Bernard, which is based on 

 Klunzinger's A. myriophthalma, is similar in this character. There is no reasonable 

 doubt that the specimens from Cocos-Keeling are both the A. myriopthalma of 

 Bernard and Klunzinger. The specimen with the denser corallum, etc., completely 

 satisfies the requirements of Klunzinger's description and figure; while, except in 

 growth-form, the characters accord with Bernard's description and figures. Bernard 

 attaches much importance to whether the growth-form is explanate, pulvinate, or 

 globular. These distinctions are not of fundamental value. Siderastrea radians 

 (Pallas) exhibits in the same species all three growth-forms; Siderastrea siderea 

 (Ell. and Sol.) is either explanate or pulvinate, as also is Porites astreoides Lam. 

 Instances of explanate, pulvinate, and hemispherical growth-form in the same species 

 might be multiplied almost indefinitely. In fact, the generalization may be made 

 that any coral which under certain conditions has a hemispherical growth-form 

 will under other, but proper, conditions produce a flattish, a slightly convex, or a 

 pulvinate colony. 



Distribution. — From Red Sea and the western Indian Ocean to Fanning Island. 

 Mr. C. Elschner collected a good specimen, now in the U. S. National Museum, at 

 the last-mentioned locality. 



