﻿PAPILLATE MONTIPOR^. 89 



or even slightly backwards. Where the corallmn begins to thicken, i.e. above the edge of the 

 epitheca, the reticulum surging up not only slightly submerges the calicles but even the 

 papillse, till only their bent up tips are left above the surface. Thus on the older parts of the 

 stock the papillas are not so conspicuous as they are on the outermost zone (3 to 4 cm. deep) 

 of the growing edge. The papillae rise to about 2 mm. in height, and are from 1 to 1 • 5 mm. 

 thick ; they often fuse into short ridges which are obviously composed of two to three traceable 

 papillae, and which run either longitudinally or transversely or quite irregularly. The appear- 

 ance of the surface is very woolly, the coarse open reticulum lying immediately below the 

 surface, and forming the core of the papillae, terminates in a thick crop of fine echinulae, 

 blunted or even slightly granular at their tips but of uniform height, so as to give almost a 

 velvety aspect to the surface. 



This description is based upon the Museum specimens, and there is very little doubt but 

 that this is the Montipora ("Agaricia ") papillosa of Lamarck. The figures of this type given 

 by de Blainville and by Milne-Edwards, appear both intended to represent the type specimen 

 in the Paris Museum, No. 255a, although they differ slightly. In de Blainville's figure the 

 arrangement of the papillse in radial ridges is very pronounced, the papillae being long ovals, 

 and morever the ridges taper away to fine points at the growing edge. This latter is not the 

 case in Milne-Edwards' figure, but the ridges are long and thick, although on the enlarge- 

 ments they are shown to be obviously formed of fused, more rounded papillae. Examination of 

 the original specimen shows that it comes about half-way between the two figures. 



In the Museum specimens the papillae (except where they first rise out of the reticulum 

 with a gradual slope) are almost uniformly round or cylindrical, and not the long oval as 

 figured by de Blaiuville and Milne-Edwards, and they are not at all so crowded as in the 

 specimens figured by these authors. Again, the serial arrangement is only conspicuous in 

 young fronds or near the growing edges. In the older parts of the coral the papillae are 

 scattered, many having been apparently submerged. 



Counterbalancing these differences, however, we have the laminate streaming layer, the 

 woolly appearance of the papillae, and the surging up of the bottoms of the valleys, and on 

 the under surface the protuberant calicles, the irregular droppings of the coenenchyma, and 

 the appearance of the laminae of the streaming layer as parallel striae for a short distance 

 round the margin, as features in common; and these, it seems to me, quite outweigh the 

 slight differences in the exact order and shapes of the papillae. 



The type specimen in the Paris Museum is said to be from Tongatabu, whereas the 

 British Museum specimens are all from Torres Strait. 



a-d. (Fragments of a large frond), Torres Strait. Prof. A. C. Haddon. 



e. (Young fronds), Torres Strait. „ „ 



70. Montipora denticulata. (PI. XVII. fig. 1.) 



Description. — Corallum explanate, more or less circular, flat or convex, growing out freely 

 and horizontally from some lateral attachment, at least 10 cm. deep ; thin, 2 to 2*5 mm. 

 thick at the edge, margin toothed or notched, each tooth corresponding with a longitudinal 



N 



