﻿PAPILLATE MONTIPOR^. 77 



shallow valleys. The corallum is built up by successive irregular encrustations, the creeping 

 margin being 2-3 mm. thick, but increasing to 7 mm. at 1 cm. from the edge. An epitheca 

 closely follows the growing edge. 



The calicles are numerous, less than a diameter apart, deep, open, very conspicuous in 

 the smooth valleys and depressions, but obscured on the lobes; about 0-75 mm., fairly 

 sharply circumscribed ; the septa irregularly and unevenly developed, sometimes small as in 

 the crowded calicles in the valleys, sometimes, as on the higher portions of the lobes, star-like 

 and symmetrical, with six well developed primaries reaching almost to the half radius circle, 

 with rudimentry secondaries. 



The coenenchyma is a delicate filamentous reticulum, in which, in sections of explanate 

 creeping edges, the middle streaming layer can be distinguished. A solid layer is frequently 

 deposited on the epitheca. The bottoms of the valleys consist of smooth, open reticulum. On 

 the lobes the coenenchyma of the narrow interstices protrudes, swelling out above the surface 

 as if squeezed out from between the calicles. These knob-like papilla are of all sizes, with 

 one, two, three or more calicles deeply sunk in their sides. These irregular rounded knobs 

 spring up in groups, and the irregularity of the surface thus formed causes the lobed surface 

 of the next growth, each lobe being again covered with these smaller papillate knobs. The 

 calicles which develop on the papillate knobs first appear as minute indentations in their 

 flat swollen tops. 



There is one large specimen of this beautiful coral. Owing to the general similarity 

 between the lobes of this specimen and the lobed portion of specimen h of Montipora 

 lanuginosa, I thought at first that the two might be connected. But closer observation 

 shows that they are quite distinct in almost every detail and that their resemblance is merely 

 superficial. In M. lanuginosa, there is nothing like the curious knobbed and calicle-bearing 

 papillae looking as if they had been squeezed out from between the crowded calicles in the 

 valleys. 



a. Diego Garcia. G. C. Bourne, Esq. (PL XIV.) (Type.) 



It is obvious that this method of papillate growth might easily give rise to branching 

 specimens. I have therefore placed under this same heading a coral from Mauritius which 

 I had arranged under spumosa, near which it seemed to come. It is, however, much nearer 

 this type ; the swollen knobs hardly differ from those of the type, excepting that they show a 

 tendency to rise as short finger-shaped processes which grow out in all directions and fuse 

 irregularly. The resulting stock is an irregular branching tuft of processes which is in gi'eat 

 contrast with the compact, lobed mass of the type specimen. In this specimen, the calicles 

 are not quite so crowded and on the average they are a little larger. 



b. Mauritius. (PL XVI. fig. 1.) 



