144 PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



Frequently tabuliform floors form across the bottoms of deep calices below the 

 level of the columella, but in some of the calices on the edge of the colony the floors 

 curve upward into the interseptal loculi above the columella level. 



Habitat, etc., Cocos-Keeling Islands— -The notes of Dr. F. Wood Jones state 

 as follows: 



"Limited to small colonies; local in distribution; found most commonly at the east end 

 of Pulu Tikus, never at the west end. Lives only on the barrier and constantly grows on 

 the underside of 'negro heads' and large boulders, or in chinks in compound rocks. It 

 nearly always grows mouth downward and away from the light. It expands only in the 

 dark." When the colony consists of one or two polyps it is colored bright chrome-yellow to 

 orange; when older it is brilliant vermillion; at all times it has an iridescence resembling 

 solutions of eosin." 



Distribution. — Cocos-Keeling Islands; Lifu, Loyalty group; Fanning Island 

 (C. Elschner). 



Ccenopsammia manni Verrill, a closely related species found in the Hawaiian 

 Islands, is vermillion while alive; C. ehrenbergiana M. Edw. and H. and C. coccinea 

 (Ehr.), from the Red Sea, according to Klunzinger, and C. aurca (Q. and G.) from 

 Australia, are also reddish in color. It seems probable that C. zoilleyi may be a 

 synonym of C. antra (Q. and G.). 



Dendrophyllia manni (Verrill). 



1866. Ccenopsammia manni Verrill, Proc. Essex Inst., vol. 3, p. 30. 



1907. Dendrophyllia manni Vaughan, U. S Nat. Mus. Bull. 59, p. 156, plate 46, figs. 6, 6a, 7, ya. 



Mr. Elschner obtained at Fanning Island a colony which was black while alive, 

 thereby differing from typical D. manni. There are on the same corallum both 

 short and exsert corallites. The columella is well developed, spongy, in some 

 instances composed of curled flakes. There may or may not be a faintly developed 

 crest along the columella summit. The columella is better developed than in the 

 specimens I figured from Kaneohe, Oahu (op. cit., plate 46, figs. 7, Ja), but about 

 the same as in Verrill's cotype (op. fit., plate 46, figs. 6, 6a); it is more vesicular 

 than in D. ivilleyi and the crest on its upper surface is less distinct. The speci- 

 men has considerable resemblance to D. coccinea Dana = D. dance Verrill, 1 but its 

 columella is coarser in texture than that of the latter. I should not be surprised 

 if large suites of specimens showed that D. aurca, D. dance, D. manni, and D. willeyi 

 were variants of the same species. 



Distribution. — Hawaiian Islands; Fanning Island (C. Elschner). 



Dendrophyllia diaphana Dana. 

 Plate 60, figures 2, 2a, Dana's type; figures 3, 3a, specimen from Cocos-Keeling Islands. 

 1846. Dendrophyllia diaphana Dana, U. S. Expl. Exped., Zooph., p. 389, plate 30 [27], fig. 3. 



A description of Dendrophyllia diaphana from Cocos-Keeling Islands is as 

 follows : 



Corallum composed of small clusters of corallites rising from a narrow base. Dimen- 

 sions of largest colony: height, 35 mm.; greater diameter in horizontal plane, 38 mm.; lesser 

 diameter in horizontal plane, about 32 mm. The daughter corallites mostly bud from near 

 the base of the parent and diverge upward, but there is occasional gemmation from just 

 below the calicular margin. The extension of the edge zone below the calicular edge seems 

 largely determined by environmental conditions; when conditions are favorable it may be 

 as much as 25 mm.; when unfavorable it may be only 2.5 mm. There is no well-developed 

 epitheca, but a few epithecal threads may mark the lower margin of the edge zone. 



'Dendrophyllia coccinea, Dana, U. S. Expl. Exped., Zooph., p. 388, plate 27, fig. 4 (Oculina coccinea 

 Ehr.) = Dendrophyllia dana Verrill, in Dana's Corals and Coral Islands, p. 384. 



