﻿TUBEKCULATE MONTIPOR^. 149 



these are long, stout, closely packed, and joined together only by very slender threads. The 

 great majority of these trabeculte rise above the surface as solid, symmetrical, globular or 

 oval, and delicately frosted tubercles, between which one can see down into the depths of 

 the coenenchyma owing to the slight development of the junctions. The tubercles are 

 tallest on the eminences, and here take the lead in forming the branches, hence the absence 

 of the typical axial reticulum. On the continuous flat tops of the processes forming the 

 tuft the tuberculate character is lost, and the surface is formed by a fine system of reticulate 

 crests deeply cut into by vaUeys and pits in which the calicles are sunk. This change in 

 the character of the surface is reached gradually by the change of the tubercles into ridges, 

 which become more and more reticular as the summit is reached. 



The single specimen of which the above is a description is unique among the 

 Montiporans in the National Collection in the character of its ccenenchyma. The crowding 

 of the tubercles, their usually perfect symmetry and delicate frosting, their leading in the 

 formation of branches, the consequent absence of an axial reticulum, are points which deserve 

 special notice. 



There is, unfortunately, but one fairly complete tuft with two long, narrow, basal 

 surfaces of fracture, which suggest that the whole tuft is due to the proliferation of a ridge, 

 the greater part of which, however, was probably dead and corroded. 



a. Townsville, Great Barrier Eeef. CoU. SavUle-Kent. (Type.) 



125. Montipora ellisi. (PL XXVIII. fig. 2 ; PI. XXXIV. fig. 10.) 



Description. — Corallum dish-shaped, concave, with steeply turned up edges, thick and 

 crumpled. From both the inner and outer faces of these edges, and from irregularities in 

 the surface of the corallum, the coenenchyma towers up to form fused masses of spikes 

 covered with ridges and crests. These aU rise to about the same height, 5 cm. from the 

 base of the dish. Epitheca only very partially developed. 



Calicles about 0'75 mm. in diameter, conspicuous, uniformly distributed from 1 to 

 1 • 5 mm. apart. Six thin prominent septa reaching to about the half radius circle ; one or 

 two directives. Secondaries just indicated. A conspicuous columella present in most of 

 the calicles on the thinner portions of the dish ; not regularly developed in the calicles on 

 the excrescences. On the under surface the calicles have the same characters but are 

 smaller. 



The coenenchyma has a thick layer of delicate laminate streaming reticulum in the 

 explanate portions, solidifying ventrally in the base of the dish, but dorsaUy changing into 

 trabeculse, stout, distinct, and bound together by a thia light reticulum. On the outer faces 

 of the curved-up edges of the dish, short, much stouter trabeculse are also formed. The 

 trabeculae give rise all over the corallum to tubercles, varying greatly in size, of uniform 

 appearance, solid, closely packed yet distinct, separated by narrow fissures which run straight 

 down between the trabeculse. These tubercles thus form the whole surface of the coral : 



