﻿PAPILLATE MONTIPOR^. 99 



76. Montipora viridis. (PI. XXXIII. fig. 10.) 



Description. — Corallum forms irregular loose clumps of thin angular branches, often 

 compressed, with very uneven surfaces, pointing in almost any direction and fusing freely. 



Calicles conspicuous, • 5 to • 75 mm. diameter, with distinct margin, primaries thick, well 

 developed, regular, reaching to near the half radius circle. The two directives frequently con- 

 spicuous, secondaries irregularly developed. Calicles frequently rise up in contact with the 

 ridges, which often encircle their apertures. Calicles also appear at the tips of the branches. 



In sections of the branches a loose open reticulum, laminate but porous, is conspicuous. 

 This carries on the tips of the branches. The radial or cortical reticular layer soon becomes 

 almost solid and glassy, but is traversed by the conspicuous polyp cavities and by a few pore 

 canals. Bound the tips of the branches the light axial reticulum rises into tall thin ridges of 

 nearly uniform thickness and different lengths ; these do not run strictly longitudinally, but are 

 more serpentine and cut one another at right angles. They appear primarily as ramparts 

 round the young calicles which open in the axial reticulum, and are of a light feathery 

 texture. As the branches thicken and the solid cortical layer appears, these ridges also 

 solidify and sink, as if partially submerged in the thickening surface layer. They then appear 

 as low rounded serpentine ridges, ornamented along their edges by a regular system of trans- 

 verse gashes ; the teeth thus caused are frosted white against the deep glass-green of the solid 

 ridge. In this condition they may twist round calicles as regular circular ramparts, the aperture 

 with a distinct margin either remaining in the base or rising to the level of the rampart. 



This unique and beautiful coral from Solomon Islands agrees with the Montipores 

 from the New Guinea region, in the olive-green colour and the delicate beauty of its surface 

 texture. There is no other known Montipore (except M. patinceformis, Esper, and M. undata), 

 showing the peculiar serpentine ridging (cf also M. hifrontalis, p. 165). In M. effusa the 

 ridges are bent at all angles, but are much more crowded, and there is nothing like the 

 serpentine arrangement seen in these beautiful specimens. 



a. Solomon Islands. Vienna Museum. (Type.) 



c. Two fragments. " „ 



d. Papillce regularly nipple-shaped or columnar. 



77. Montipora planiuscula. 

 Montipora planiuscula, Dana, Zoophytes (1848) p. 507, pi. xlvii. figs. 3, 3a. 



Description. — Corallum encrusting, glomerate, smooth surface, nearly 8 mm. thick. 

 Cells large, deep, sunk, indistinctly 12-rayed. 



Coenenchyma swells up in the interstitial spaces into marked convexities, which 



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