﻿TUBERCULATE MONTIPOR^. 163 



the tubercles, may stand right up cup-shaped. Similarly, the feathery ridges of the streaming 

 layer near the growing edges are generally associated with young calicles. 



The finer details given in this description are taken from the only specimen of this kind 

 in the National Collection. I have, however, seen others, notably a fine series in the Paris 

 Museum, wliich probably differs from the above in some details, and also in the extraordinary 

 profusion with which the edges of the fronds fray out, rising up into tall ragged flames ; these 

 in old stocks may completely obscure the bowl stage of the stock, which may ultimately 

 become a taU, erect, tapering compact bundle of crumpled ragged flames. My notes contain 

 no information as to the locality of these specimens. 



In the base of the bowl in the British Museum specimen a large Ophiurid was 

 imprisoned. 



a. Locality not recorded. 97. 5. 18. 5. 



6. Eight fragments of same. 97. 5. 18. 4. 



Types. 



133, Montipora plicata. (PL XXXIV. fig. 14.) 



Descrijotion. — Corallum consists of clusters of leaves (form of grouping unknown), about 

 10 cm. long and 6 wide ; these are either flat or with the sides curled up. The growing edge is 

 thin, from 2 to 3 mm. A well developed epitheca follows to within 2 to 5 mm. of the 

 edge. Crumpling of the leaves is very common ; the sides fold under, and thick, knobbed 

 and irregular plates, some 7 mm. thick, are formed from which all symmetry is lost. 



The calicles are numerous but unevenly distributed ; on the thin leaves they are more 

 than • 5 mm. in diameter, but on the thicker irregular expanses they reach to nearly 1 mm. 

 Wherever the ccenenchyma is very richly developed into ridges and tubercles, the calicle 

 apertures tend to protrude as thin, delicate, membranous rings from the inner face of which 

 twelve short but symmetrically arranged septa project, there being often no great difference 

 between the two cycles. These leave a large open fossa which is very deep on the thicker 

 crumpled leaves. 



The ccenenchyma. The sections show a laminate streaming layer with a solid deposit on 

 the epitheca. This deposit may be over 1 mm. thick. The surface shows great variation. 

 Thin leaves may be merely traced over with very thin gyrating ridges which form angular 

 patterns round the calicles and combine somewhat to give an appearance of longitudinal 

 ridging. These longitudinal ridges may stand up very prominently and over.shadow the 

 rest. On thicker and apparently more horizontal leaves, these longitudinal ridges may 

 break up into short lengths so that the whole surface may be covered with thin, flat points or 

 square plates, 1 • 5 mm. high, arranged for the most part in longitudinal rows not more than 

 1 mm. apart, and between which calicles with their protuberant membranous m^argins open. 



On stiU more irregular leaves, the longitudinal arrangement of these plates may be lost 

 and they may run together at all angles or rise to great heights, 4 mm., and crested processes 

 may arise, while on the more level surfaces large tubercles may appear. 



Y 2 



