So PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



Pocillopora woodjonesi, new species. 

 Plate 22, figure 3, view of a branch; plate 24, figure 3, calices. 



The following is a description of the species: 



Corallum somewhat similar in growth-form to P. eydouxi, "but the branches tend to 

 be more dwarfed and to become fan-shaped instead of elongate." 1 The branches are short, 

 more or less contorted plates. Depth of living tissue 38 to 62 mm.; width of branches, 38 

 to 73 mm.; thickness just below summits, 7.5 to 10 mm. The widest branch rapidly narrows 

 toward its base; 62 mm. below summit the width is 32 mm. Summits without verruca?. 

 Texture relatively light. 



Verruca? well developed or obsolete on the sides of the branches. Where well developed, 

 usual diameter at base about 3 mm.; height about the same; summits rounded; distance 

 apart about 2.5 mm. The size ranges from mere swellings on the surface up to that stated; 

 one large verruca has basal diameters of 4 by 5.5 mm., height 3.5 mm. In attitude they 

 are perpendicular to the surface or inclined; in places they may be fused by their bases so 

 as to form longitudinal series. 



Calices on branch summits separated by thin walls; diameters 0.5 to 0.7 mm. On ver- 

 ruca?, walls 0.25 to 0.5 mm. thick; diameter of calices, as much as I mm. Near base of living 

 tissue, walls from about 0.5 mm. or somewhat less up to I mm. across, diameter of calices 

 about 0.75 mm. Calicular fossa a rather deep pit. 



Septa very distinct in the calices on the sides of the branches, but situated rather deep 

 down; number, 12, sube<iual in size, do not reach the center, plane of symmetry indistinct. 

 Columella a minute style, rising from a floor below the inner edges of the septa. 



Ccenenchyma thin; granulations radially compressed, often forming costal striations 

 around the calicular edges, lops truncated, with secondary frosting. The ccenenchymal orna- 

 mentation is strikingly different from that of P. eydouxi. 



The longitudinal section shows an astonishingly great development of cellular tissue, 

 10.5 mm. thick, with onlv a surface membrance of compact ccenenchyma outside it. A 

 fragment from another colony is 11 mm. thick on the base; cellular tissue, about 7.5 mm. 

 The corallum is, therefore, much more porous and lighter than in P. eydouxi. 



Habitat, etc., Cocos-Keeling Islands. — Dr. Wood Jones states: "From the deeper 

 barrierpools,colorpinkorbrown,moreoftenbrown; exposed parts of the zooids brown!' 



I have discussed in my paper on Hawaiian 2 corals most species of Pocillopora 

 which have well-developed septa and columella? and have nothing new to add. 

 P. woodjonesi accords with none of the previously described species known to me. 

 Its nearest relative seems to be P. eydouxi. 



Family STYLOPHORIDjE Verrill. 



Genus STYLOPHORA Schweigger. 



1820. Slylophora Schweigger, Handb. Naturg., p. 413. 



1857. Slylophora Milne Edwards and Haime, Hist. nat. Corall., vol. 2, p. 133. 



Type species: Stylophora pistillata (Esper). 



Stylophora pistillata (Esper). 



Plate 26, figures I, la, specimen from Murray Island. Also plate 18, figure 40, of Dr. Mayer's article. 



1906. Slylophora pistillata von Marenzeller, Denksch. k. k. Akad. Wiss. Wien, vol. 80, p. 77, plate 36, figs. 

 94-98; plate 29, figs. 94*1-980. 



Plate 26, figure I, represents an excellent specimen about 20 cm. tall. The char- 

 acter of the branches and calices are well represented by Klunzinger's St. digitata 

 (plate 7, fig. 5 ; plate 8, fig. 1 ), which von Marenzeller places in the synonymy of St. 

 pistillata. Surface of corallum rough, upper corallite wall produced, lower obso- 

 lete; primary septa thick. 



Dr. Mayer obtained a stunted specimen represented by plate 18, figure 40, in a 

 shallow pool on the Lithothamnion ridge. 



Stations. — Off the northwest reef of Murray Island, depth 18 fathoms; in pro- 

 tected, quiet water; bottom mud, with rocky patches. 



'From notes of Dr. Wood Jones. 2 U. S. Nat Mus. Bull. 59, pp. 93-97, 1907. 



