﻿PAPILLATE MONTIPOE^. 91 



71. Montipora pulcherrima. (PI. XVII. fig. 2 ; PL XXXIII. fig. 7.) 

 Montipora prolifera* Bassett-Smith {non Briiggemann), Ann. and Mag. Nat. Hist., (6) vi. (1890) p. 450. 



Bescnption. — Corallum explanate, slightly scallop-shaped. Living zone about 10 cm., 

 growing edge very thin, 1 mm. Thickest part from 3 to 4 mm. An epitheca from 2 to 4 

 cm. from growing edge. Numerous pendent knobs on the under surface (5 to 6 mm. in 

 diameter) are slowly grown over by the epitheca. 



Calicles minute, 0'25 mm., and scattered, in all the thinner parts (i.e. for some 5 cm. 

 from the edge) raised as small irregular cylinders or hoods above the surface. Six primaries, 

 thick, granular and irregular, reach to about the half radius circle, secondaries only here and 

 there incompletely developed. 



On the under surface the calicles are mostly raised on slight eminences, which may 

 develop into the pendent knobs by the secondary proliferation of the reticulum. Calicles 

 appear on the sides of the knobs. 



The coenenchyma shows in section the typical streaming reticulum, resting upon a dense 

 layer deposited upon the epitheca ; the layer forming the upper surface is sharply differentiated 

 from the underlying streaming layer by being granular and nodulated and rather compact. 

 This dense reticulum rises up abruptly into taU flat plates of nearly uniform thickness, 

 generally arranged longitudinally in the line of growth, sometimes flowing together to form 

 tall coarsely toothed ridges. These-plates and ridges reach a height of 2 '5 mm., and are less 

 than 1 mm. thick. They are often slightly wavy and may even bend over sideways. Here 

 and there on the coral these ridges or series of plates and papillae may be so close together 

 and regular as to remind one of the jagged septa of a Pungia. A section across one of these 

 papillae reveals the dense reticulum immediately under the surface, which itself is finely granular 

 and almost smooth to the naked eye. In the troughs between the ridges the calicles appear on 

 small cup or cylinder-like prominences. On the under surface the coenenchyma has a solid 

 appearance, but the proliferation of the reticulum which gives rise to the pendent knobs is a 

 very loose, open filamentous sponge-work. 



There are four specimens, the largest in three fragments which fit together to form a 

 scallop-shaped stock about 10 cm. deep by 10 broad. The specimens were labelled M. pro- 

 lifera by Bassett-Smith, owing to the resemblance between the ridges on the young fronds of 

 that type and on this specimen. There is, however, no proof that these ridges, which are more 

 pronounced and regular than on the young fronds oiprolifera, ever develop as they do in that 

 type. Again, the youngest specimen of this coral is very different from the youngest frond of 

 prolifera. It is a beautifully rich pink and yellow peach colour, the ridging is very irregular 



* Printed by mistake " M. prolifica, Briiggemann MS.? " 



N 2 



