MADEEPORA. 91 



primary septa become confluent and form a solid axial rod, which is often rounded and 

 nodular at its apex. This form may prove to be a distinct species. 



Amboina ; Solomon Islands. 



a. Amboina. H.M.S. 'Challenger.' 86. 12. 9. 287. 



(Type = il/. effusa^ Quelch.) 

 6. Treasury Island, Solomon Islands. Dr. Guppy [P.] . 84.12.11.21. (Var. paradoxa.) 



83. Madrepora cerealis. 



? Madrepora muricata, var., Esper. Pflanzenth. Fortsetz. Th. i. pi. liii. 



Madrepora cerealis, Dana, Zoophytes, p. 460, pi. xxxv. fig. 2 ; M.-Edwards & Haime, Coralliaires, t. iii. 

 p. 151 ; Verrill, Bull. Mus. Comp. Zool. 1864, vol. i. p. 42 ; Studor, Mitth. naturf. Ges. Bern, 

 1880, p. 22 ; Quelch, ' Challenger ' Reef Corals, p. 153 ; Rathbun, Proc. U.S. Nat. Mus. 1887, 

 vol. X. p. 13 (nan Ortmann, Zool. JB. 1888, Bd. iii. p. 152). 



Madrepora secale, Quelch (non Studer), ' Challenger ' Reef Corals, p. 163. ■ 



Corallum broad cespitose, somewhat convex ; not complanate below, but this may be 

 owing to the type not being a full-grown specimen; it measures 12-5 cm. in height and 

 15 cm. in diameter. Branchlets numerous, erect, spiciform, 6 to 8 mm. thick and 5 mm. 

 long, not terete, very unevenly covered with corallites, some of which are long and 

 proliferous. Axial corallites 1-5 mm. diameter, a little prominent. Radial corallites 

 appressed, subtubular, unequal, 2 to 3 mm. long,, subrostrate, exterior smooth ; aperture 

 elliptical ; star very short and imperfectly distinct ; the directive septa are a little prominent. 

 (Dana.) 



A specimen in the collection, from Wreck Bay, agrees almost exactly with Dana's 

 figure. The axial corallites are cylindrical, 2 mm. diameter, and have a rather dense wall. 

 Radial corallites tubular, with subimmersed to labellate or half-tubular ones between. The 

 more prominent tubular corallites often have the inner part of the wall as prominent as the 

 outer, and are frequently arranged in irregular longitudinal rows ; length 2 to 4 mm., 

 diameter 1*2 to P8 mm. The axial corallites have only 6 septa, and the directives are rather 

 broader than the others. In the tubular radial corallites the directive septa are broad and 

 subcqual, but are situated deep down ; the other primary septa are either absent or very 

 naiTow. In immersed and subimmersed corallites the septa are better developed. In a speci- 

 men from Mauritius the tubular radial corallites have rarely a circular aperture, and the 

 axial corallites show indications of a second cycle of septa. In the specimens which form 

 part of Mr. Saville-Kent's collection the aperture of the radial corallites is still more oblique 

 and often slit-like. 



The ' Challenger ' specimens referred by Quelch to M. secale and M. cerealis appear to 

 me to belong to one species, but differ in several points from typical M. cerealis. The speci- 

 men referred to M. secale is a small corymbose clump in which the marginal branches 

 extend a little obliquely, but are not fused together. 



The other specimen is considerably larger and a fusion takes place between the main 

 branches, which are prostrate and subcoraplanate below. The under surface is provided with 

 short stunted branchlets in the general plane, and with appressed, tubular, or verruciform 

 corallites. There is here a general resemblance to M. assimilis, but on the upper surface the 



