﻿150 MADREPOEARIA. 



there is no level interstitial surface between them. They are taller, stouter, and more 

 feathery on eminences or on the sides of upgrowths. On the under sides of the coral the 

 tubercles are stouter, smoother, more solid and compact. Towards and on the tops of the 

 crests and ridges the tubercles are replaced by undifferentiated coenenchyma of the reticular 

 streaming layer, which froths up into spikes and ridges with deep narrow valleys and holes in 

 which, seen under a lens, calicles open ; tliis foaming reticulum is formed of fine plates richly 

 perforated with round pores. At the creeping edges of fresh explanate growths the reticulum 

 is delicate and foam-like. 



The single specimen of tliis type was originally named by Briiggemann " M. stylosa, 

 Ehrenberg." It, however, bears no resemblance to the photographs of that type given by 

 Dr. Klunzinger. 



The proliferation of the ccenenchyma is singularly beautiful. The whole surface is 

 formed by a mosaic of distinct tubercles separated by deep fissures ; they are flat and plate-like 

 on the lower, more solid parts of the under surface, but round, smootli, and solid or bushy, on 

 all the rest of the siu'face. Further, the change of the tubercles into ridges and tall spike-like 

 crests all pointing upwards are features deserving special attention ; the crests being softer 

 looking and rounder than are the somewhat similar developments on M. foliosa. 



The only other Montipore which I have seen apparently resembling it is a conical cup 

 open at the base, wliich is in the Paris Museum, No. 260ft. 



a. Locality not recorded. G. B. Sowerby, Esq. 38. 1. 8. 3. (Type). 



126. Montipora efflorescens. (PI. XXVIII. fig. 1 ; PI. XXXIV. fig. 11.) 



Description. — Corallum a confused mass of towering stems fusing irregularly together, 

 each thickly covered with small lobes or branchlets pointing upwards. The whole mass rises 

 from the surface or edge of an encrusting layer 0*5 to 1 cm. thick. 



Calicles conspicuous, neatly star-shaped to the naked eye, ■ 75 mm., irregularly distri- 

 buted, here densely crowded, there scattered. The primaries well developed, stout, reaching 

 to the half radius circle ; directives. The secondaries distinct but small. Margin of the 

 calicles clear ; fossa deep. 



Coenenchyma a very pronounced streaming layer of delicate reticulum in the axes of the 

 stems, and resting upon a solid basal layer in the encrusting portion of the corallum. This 

 streaming layer proliferates at the tops of the stems and at the tips of the branchlets. In the 

 latter it runs up as longitudinal ridges into elegant groups of tall, woolly and round-topped 

 points and turrets, while on the flattened tops of the main stem it rises into angular systems 

 of tall crests with deep narrow valleys in which star-like calicles open. Below these growing 

 points and surfaces the reticulum runs out into tubercles rising from stout and very distinct 

 trabecule.. Almost the whole surface of the corallum, other than the crested parts named, is 

 thickly crowded with small granular tubercles which are for the most part very uniform in 

 size, under • 5 mm. in height and thickness. 



