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



Apparently there is no doubt regarding the type of this species, as Klunzinger 

 states in the explanation of his figure "Exemplar von Ehrenberg aus dem Rot hen 

 Meere, No. 726 des Mus. Berol. (als Astrcea pectinata)." Klunzinger says in his 

 text: "Von den Dana'schen Arten steht Astr. favistella oder sinuosa die sehr wohl 

 am nachsten." . 



Apparently I have confused the nomenclature of these corals by misidentifying 

 specimens brought by Dr. Gravier from Djibouti, French Somaliland, referring them 

 to G. pectinata instead of to G. planulata; and in my opinion Matthai has committed 

 the same error in designating his plate 28, figure 6, and plate 37, figure 1, as G. 



pectinata. . 



Dana's type of Astrcea favistella is illustrated by plate 42, figures 4, \a, and his 

 type of Astraa sinuosa by plate 43, figure 1. The type of Astrcea favulus, which 

 seems to belong to the same species, is represented by plate 42, figures 3, 3a. There 

 is in the U. S. National Museum a fine suite of this species from the Philippine 



Islands. 



The following is a description of the specimen represented by plate 43, figure 2, 

 taken about 700 feet from shore on the southeast reef, Murray Island: 



Corallum arched above, margins irregular; dimensions, 76 mm. long, 68 mm. wide, 

 4.0 mm. thick. Relatively heavy. . 



Calices polygonal in outline; width about 5 mm.; length in those undergoing hssion up 

 to Q mm., usually less. Depth 4 to 5 mm. . 



Intercorallite walls sharp on the summit, except in places near the periphery, but 

 slightly below the edge they are thickened up to 1.5 mm. Near the periphery of the corallum 

 the thickness may somewhat exceed 2 mm. 



The septal ends of adjacent calices may be opposed; usually a rudimentary septum is 

 opposite a larger one, or they may alternate. The upper margins rise very slightly above 

 the edge of the wall. For about I mm. from their outer ends the upper edges slope very 

 slightly they are almost horizontal, then they curve downward and the inner edges tall 

 almost perpendicularly to the bottom of the calices. The upper septal margms have a 

 strikingly flattened appearance, strongly contrasting w.th C. rctijornns. I he septal edges 

 finelv and regularly dentate. Faces with minute, usually blunt granulations 1 otal number 

 of septa about 40 in a calice S by 6.5 mm. in diameter; of these, 14 reach the columella, 10 

 are shorter, and the others are rudimentary, some scarcely visible. More than 12 septa 

 usually reach the columella, and have on their inner ends erect pahform lobes, with rounded 

 upper margms and granulate sides. The pali resemble those of G. retiformis. 



The columella is trabecular, occurs in a depression below the palar crown, and is about 

 1 mm. in diameter, slightly less than one-quarter the diameter of a calice. 



This description fits Dana's type of A. sinuosa, except that the upper edges of the septa 

 in the latter on the average are more sloping and some calices therefore look more open; 

 otherwise a description of one specimen fits the other. 



Dr Mayer obtained 20 other specimens of Goniastrea pectinata on the Murray 

 Island reef The variation is simply bewildering. In order to illustrate it the fol- 

 lowing figures have been made (plate 43) : figure 2, specimen on which the foregoing 

 description is based; figures 3, 3 «, views of calices on opposite ends of the same 

 specimen; figure 4, calices of a third specimen; figures 5, 5«> views of calices on 

 opposite ends of a fourth specimen. 



The principal variation is in the character of the wall between adjacent coral- 

 lites and in the depth of the calices. In general when the walls are wide the calices 

 are shallow. The walls are widest, up to 3 mm., in young incrusting colonies and 

 near the edges of older colonies. Usually on the summits of domed, healthy speci- 

 mens the upper edge of the wall is acute, but is thickened below by curved, sloping 

 dissepiments which occur in a zone outside more slightly curved dissepiments. 



