﻿PAPILLATE MONTIPOR^. 109 



show any trace of having formed nipple-shaped papillae at its different levels. For it is often 

 possible in thick papillate forms to trace the buried papillae quite clearly in the arrangement of 

 the reticulum (cf. M. ambigua). Specimen a is a slightly larger and more obviously encrusting 

 specimen, with slightly coarser reticulum, thicker septa and more conspicuous calicles ; the 

 echinulse are also more pronounced. Free edges appear, supported by an epitheca. Young 

 calicles develop in rows on the outermost faces of the growing edge. 



Although both these specimens are very small, they appear to be growing perfectly 

 normally and to be practically complete stocks. They thus claim to constitute a separate 

 type, there being no other such small encrusting papillate Montipores. 



a, h. Bu-d Island, Seychelles (7 fathoms, H.M.S. ' Alert.' (Types.) 



sand and coral). 



83. Montipora sinensis. (PI. XIX. fig. 3 ; PI. XXXIIL fig. 11.) 



Description. — CoraUum thick, encrusting, with free edges 5 mm. thick and rapidly 

 thickening to 1*5 cm. A well developed, wrinkled epitheca to within 1 cm. or less of the 

 edge. 



Calicles inconspicuous, delicately star-shaped, • 75 mm., sunk somewhat below the surface 

 of the coenenchyma as indentations, the floors of which are formed by the close star-like 

 arrangements of the septa. Two cycles of long septal teeth, the primaries crossing the half 

 radius circle, two often more pronounced as directives. To the naked eye the septa seem to 

 fill up the cavity so that no dark fossa is visible. On the free under surface the calicles are 

 very minute, • 5 mm., and under the pocket-lens project as thick single rings with irregular 

 saw-like septal teeth on the inner margin. 



Coenenchyma in section is very dense ; a solid layer may be deposited on the epitheca. 

 The upper surface is an echinulate, flaky reticulum with a soft woolly aspect to the naked eye. 

 Papillae, more conical or long-cylindrical than nipple-shaped, rise up irregularly in the inter- 

 stitial spaces without filling them, 1 ■ 5 mm. high and • 5-0 ' 75 mm. thick. They stand, as a 

 rule, isolated, but here and there they fuse together ; between the papillae the coenenchyma 

 sinks down into concavities, in marked contrast to the tall papillae. Eound the growing edge 

 for about 1 cm. papillate ridges appear, twisted and bent, as if produced by a shrinkage of the 

 surface. The coenenchyma of the under surface is a smooth, rather dense reticulum. 



The specimen a, on which this description is founded, appears to have been, in life, of a 

 rose-pink colour. This type is probably allied with M. tuberculosa of Lamarck, from which, 

 however, it differs mainly in the size of the calicles, which are much smaller in Lamarck's 



type. 



There is a second specimen, which so closely agrees with this in the specialisation of the 

 coenenchyma and in the concave intervals between the papillae that I place it under this head, 

 although it is much thicker (3 cm.), and the calicles, though of the same general character, have 



