CORALS FROM MURRAY, COCOS-KEELING, AND FANNING ISLANDS. 201 

 The following is a brief description of the Murray Island specimens- 



L ahces about as in P. mayeri. muyen. 



Wall membranous, elevated, and more or less zigzag where the reticulum is not rWI 

 oped; where the reticulum is developed it usually can be traced The ret Icll it . 



The senrn „ ^! f" V",' u" u hlch - the rad . lal structures are more conspicuous 

 1 he septa, pall, and columella of both species are similar in arrangement. 



The difference between the two, therefore, consists in the greater development 

 of the radial structures in the reticulum of P. mayeri, while in P. viriTtherTkl 

 greater development of the tangential and horizontal structures, and there i in 

 the latter a membranous wall, which may be zigzag. (See note at end of discus on 

 ot f. mayeri, page 197.) 



Stations, Murray 1 stands. -Southeast reef, line I, 600 and 1,000 feet from shore 

 Distribution— Fiji Islands; Murray Island. 



12. Porites densa, new species. 

 Plate 89, figures 2, 2a, lb, specimen from Murray Island. 



The following is a description of this species: 



Corallurn with incrusting base; edge shows younger growths over the older- upper sur 

 face irregularly rounded, but not thrown into gibbosities or rising into lobes or ridges 

 fnee Cahces . cons P lcuous ; diameter measured between thecal summits, up to 2 .c mm The 

 fossa, are pits, sunk into a wide mural reticulum. Diameter of the pits 0.7/ tTi mm 



the catlaTpks!' 5 "^ """' the ^ ° f the reticulum therefoie exceeds the d°ame£r of 

 The mural trabecular usually project above the reticulum so as to form a traceable ridee- 

 then ends are irregular ,n shape and size, but radially compressed and incompletely fused 



Septa usually i 2 , sometimes 1 1, in number, thick, considerable irregularity in arrange- 

 ment interseptal locul, narrow, irregular in size. Usually 2 lateral pairf a solLry (d3) 

 directive, and a ventral triplet may be recognized, but one member of a pair may be shor 

 rendering the pair-fusion incomplete. Whether the short member of the paF is dorS I or 

 ventral with reference to the long member seems inconstant. The short sepfum, however is 



£d' h \b re ' S lrregula , nt y '"the condition of the triplet, but the lateral members are rarely 

 fused by their inner ends to the directive. »«"cijr 



P ^/^° Uter W^'f rin S ' r s stro "g'y developed. It occurs somewhat below the upper 

 edge of the mural trabecular and forms a coarse inner wall. Frequently an irregularly shTped 

 tooth granulate on the end, stands up on the septal margin at the inner edge of the rin^o 

 a flatt.sh, thick tooth may project inward, sloping upward at a relatively low angle There 

 is conspicuous irregularity in the septal teeth, but the persistent presence of certain teeth 

 which project inward ,n nearly horizontal planes or incline upward at low angles, is striking 

 Between the synapticular ring and the mural trabecular the septa are greatly thickened with 

 the result that the mural, synapticular, and outer septal structures form a relatively deme 

 reticulum between adjacent cahcular fossar. Because of the subhorizontal teeth, the reticu- 

 lum presents a flaky appearance. iclilu 



Deeper down in the calice one or two subhorizontal teeth project inward on each 

 septal margin. There are no definitely, developed pali, but on the inner ends of some 

 septa are irregularly shaped knots The inner synapticular ring is irregular in development 

 rarely complete Columella,- tangle irregular in development, composed of thick, irregularly 

 bent, fusing prolongations from the inner septal ends and some synapticular. Because of the 

 irregularity ,n the length of the septa, the incompleteness of the inner synapticular ring, and 



nr^Tr I V ^^ P™ 1 ° n ¥ M ' on f lnto the columnar tangle, the inner ends of 



interseptal loculi are correspondingly irregular. 



Usually there is a columellar tubercle, represented by an axial knot rising above the 

 columella, tangle, but there is no persistent axial trabecula terminating in a tubercle, as in 



