﻿APPENDIX TO THE GENUS MONTIPORA. 183 



Coenenchyma sliows in section a thin, finely reticular streaming layer, resting on the 

 epitheca. From this, trabeculae arise, long, stout, not too compact, joined by thick, irregular 

 junctions, which are in marked contrast with the thin septa, also seen in sections. The trabe- 

 culae rise as round-topped tubercles, fairly uniform, and ending all on the same level. Those 

 arranged as rings (7 to 8 in each) round the calicles, are slightly larger and taller. On raised 

 portions of the surface, the tubercles are more solid and plate-like, densely packed and fusing 

 together to form a continuous even surface, while in depressions they are thinner, more thread- 

 like, and distinct. 



The type specimen is a fragment from Funafuti, also one of the sequi-tuberculate group. 

 While approaching both M. granidata and M. myriophthalma it cannot be united specifically 

 with either — that is, without more evidence. It differs from M. granulata in not having the 

 free trabeculte, nor the sharp contrast between the thick streaming layer of delicate reticulum 

 and the pronounced trabecule, and further in the distribution and size of the calicles. 



From M. myriophthalma it differs in the absence of the solid layer, in the shape of the 

 trabeculte, and in the character and distribution of the calicles. 



a. Funafuti, EUice Islands. Coll. Gardiner. (Type.) 



142. Montipora willeyi. 



Description. — Corallum explanate, encrusting, with narrow, free, but drooping or pendent 

 and hence somewhat crumpled edges which are very friable and vary greatly in thickness 

 from 2 to 7 mm. Whole surface of the coral raised into irregular mounds by the unevenness 

 of th-e substratum. Thickness of encrusting layer very variable, average 6 mm. An epitheca 

 supports the thinner edges but remains behind under the thicker, more friable edges. 



Calicles about • 75 mm., irregularly distributed in a network of lines, the calicles in the 

 lines being almost in contact, the clear spaces being sometimes 2 to 3 mm. across. Two cycles 

 of septa, symmetrical but very short and insignificant round the margin, better developed down 

 in the deep, open, funnel-shaped fossa. Most of the calicles appear as if raised and slightly 

 tilted towards the growing edge, while near to the edge itself they frequently stand up a little 

 with an irregularly protuberant proximal wall. The calicles first appear on the friable edges, 

 and are at first only distinguishable from meshes of the laminate reticulum by their circular 

 form. Those which bend downwards towards the lower siirface become more and more con- 

 spicuous as membranous rings until they are corroded by the epitheca. 



The ccenenchyma consists of a streaming layer, the lamina of which, while distinct 

 enough to make a clear line pattern at the growing edge, are yet so perforated that the 

 longitudinal section appears filamentous. It varies greatly in thickness and is generally very 

 thick, but soon sohdifies upon the epitheca, and from the solid layer thus formed, which 

 may be 3 or more mm. thick, a dense trabecular layer rises ; the trabecule are very 



