144 MADEEPORARIA. 



proliferations is quite indistinct, usually only the directive septa are recognizable. Corallum 

 very porous ; surface spongy-reticulate, becoming regularly reticulate below ; wall striate and 

 fenestrated, margin not rounded. 



Pacific Ocean. 



a-c. Samoa Islands. Rev. S. J. Whitmee [P.]. 75. 10. 2. 18 to 20. (Types.) 



148. Madrepora scherzeriana. 



Heteropora Tiemprichii, Haeckel (non Ehrenberg), Arab. KoraUen, pi. iii. fig. 6. 



Madrepora scherzeriana, Briiggemann, Abhandl. naturw. Ver. Bremen, 1877, Bd. v. p. 397, pi. viii. ; 

 Klumzinger, KoraUenth. d. roth. Meeres, Th. ii. p. 9. 



Corallum cespitose; branches thick and stunted, little divided, 15 mm. thick, with here 

 and there a short ascending proliferous twig. Axial corallites little larger than many of the 

 radial ones, 3"5 mm. diameter, wall thick and porous, margin rounded, aperture 0*5 mm., 

 star well developed. Radial corallites irregular, but placed in rows near the apex of a branch. 

 On the distal part of a branch the majority are short, stout, tubular, with a rounded margin 

 and striate wall, a little unequal in size, but many nearly as stout as the axial corallites, with 

 immersed ones between. The lower part of the branches bear thick verruciform corallites 

 and immersed ones at the base. Coenenchyma very spongy and echinulate. 



The branches bear numerous bud-corallites up to 8 mm. long and 5 mm. thick ; these 

 gradually increase in importance towards the base of the colony, where they form twigs 

 3 cm. long. The species differs from M. seriata in the more pointed and more proliferous 

 branches, and the inner part of the corallite-wall is rarely incomplete. 



A specimen in the Collection from Ceylon which appears referable to this species has 

 the branches 6 to 8 cm. long and 1 to 1'5 cm. thick, little divided, and scarcely tapering 

 excepting near the apex. Axial corallites 3 to 4 mm. thick, hemispherical, or with rounded 

 margin. The prominent radial corallites are chiefly stout, tubular, or dimidiate, many are 

 3"5 mm. diameter and 5 mm. long, and the majority are 2*7 to 3 mm. diameter, with a thick 

 wall and rounded margin, with a few small subimmersed ones between. The aperture is by 

 no means always central ; usually the inner part of the wall is shorter and comparatively 

 thin until the corallite has attained its full development. Proliferous corallites are numerous, 

 and may attain a length of 1 cm. The septa are arranged in two well-developed cycles ; in 

 many of the radial corallites the outer directive is much broader than the others. Corallum 

 very porous ; surface spongy -echinulate ; wall substriate and echinulate. 



Yar. spongiosa. 



A form which may be a variety of this species is remarkable for its extreme porosity. 



It is subarboreseent in habit. The branches are 10 cm. long and TS to 2 cm. thick, 



gradually tapering to an axial corallite 4 mm. in diameter. The corallites on the apical 



part of a branch are similar to those in the Ceylon specimen, but 3 cm. below the apex the 



