﻿TUBEECULATE MONTIPOR^. 129 



There is no dense layer resting on the epitheca. The trabeculte of the thickening layer are 

 short, stout, very smooth and glassy, but of very irregular shapes. These rise regularly above 

 the surface as finely branched but minute tubercles averaging 0*5 mm. high, crowded, evenly 

 distributed over the whole surface except just round the growing edge. Though branching, 

 they are so small as to appear compact to the naked eye, like minute white seeds with which 

 the whole surface is evenly strewn. They rise straight up from the walls of the calicles, and 

 are arranged as single rows between the more crowded calicles, but in other parts packed 

 closely together so as to fill up the whole interstitial space. The ccenenchyma of the under 

 surface is smooth, the minute calicles opening in a close, solid reticulum, each aperture being, 

 as a rule, surrounded by a single thick ring, notched on the inner circumference in such a way 

 as to show two cycles of septa. 



The single specimen is one of the ' Challenger ' reef corals from Amboyna, and was identified 

 by Mr. Quelch with Verrill's Montipora patula. It certainly belongs to the same tuberculate 

 group, but, according to the structural variations here adopted as of systematic value, it must be 

 separated from it owing to the very different character of the ccenenchyma (see p. 144). The 

 peculiarly regular size and distribution of the tubercles, as if the whole surface were evenly 

 strewed with minute white seeds, would certainly have been mentioned by Verrill had it occurred 

 in his specimen. The method of growth of the specimen horizontally across the tips of 

 branching Madrepores is probably not accidental, inasmuch as the protrusions of ccenenchyma 

 through the epitheca appear to be a provision for the finding of fresh points of attachment. 



a. Amboyna. H.M.S. ' Challenger.' (Type.) 



106. Montipora granulata. (PI. XXXIV. fig. 1.) 



Description. — Corallum forms large explanate fronds with thin edges, 2 mm., slightly wavy, 

 but not bent up. The centre of the frond dies away, the living zone being about 8 to 10 cm. 

 deep. The frond gradually attains a thickness of 7 to 8 mm. The epitheca appears in irregular 

 patches. 



The calicles tend to be arranged in irregular wavy rows, roughly parallel with the growing 

 edge and about 1 mm. apart. Within the rows the calicles may be almost in contact. They 

 are about • 5 mm. in diameter, and conspicuous in the older, thicker portions of the corallum, 

 but obscured in the younger parts by the irregularity of the clumps of surface tubercles. The 

 primaries are well developed and reach to the half radius circle. The absence of secondaries 

 renders the interseptal loculi large and conspicuous. On the under surface the calicles are 

 numerous and minute, often mere pinholes, with six septa. 



The ccenenchyma has a well developed, lamellate streaming layer, which passes both 

 upwards and downwards into trabecular layers. In the lower the trabeculte are not very well 

 defined, short and compact, and tend to make the surface dense. The upper layer is remark- 

 able for its tall, nearly smooth, cylindrical trabeculse, hardly joined together at all but standing 

 side by side close together. Abrasion of the surface causes them to tumble out. Their tips 



s 



