﻿TUBEECULATE MONTIPOEuE. 165 



processes above mentioned. The under surface is a close reticulum covered with small 

 granules or groups of granules. 



The only specimen representing this type is a small fragment which there is reason to 

 believe is one of the specimens of the Lister Collection from Tongatabu which was somehow 

 overlooked and not labelled. If so it is specially interesting owing to its many points of 

 resemblance with M. calcarea. As stated in the description of that coral, I was long in doubt 

 whether it was not merely a corroded specimen of the coral now described. I do not, 

 however, go beyond suggesting this possibility, as there are serious difficulties. For, while it 

 is possible that the very thin tubercles and echinulse of M. hirsuta might corrode off, leaving 

 only the membranous ridges which characterise M. calcarea, it is strange that the septa should 

 be so clearly cut and preserved. It is true, of course, that the dead mass of the oral disc 

 and subjacent oesophageal and mesenterial tissue might protect the septa from corrosion a 

 little longer than the thin skin could the echinulse ; still, the closer I compare the types, the 

 less inclined am I to consider them identical without further evidence. 



We must therefore consider this as a separate species, closely resembling M. calcarea in 

 coarser structural features, but very different from it in the presence of tall, thin, glassy 

 tubercles run out into fine hairs. These often unite to form very thin gyrating, ridges like 

 membranes with ragged edges. The rising groups of calicles with ^thin, funnel-shaped 

 ramparts are common to both types, and in both, these may form tall, thin, stick-like processes. 



In its great friability, the specimen reminds one of M. friabilis, but there is no other 

 likeness. 



a. Tonga (?) J. J. Lister, Esq. (Type.) 



135. Montipora bifrcmtalis. 



Description. — CoraUum thin, encrusting, with free lobate edges, the lobes curve upwards, 

 and are at the edges shallow spoon-shaped. Edge slightly frilled, thin, 1 to 1*5 mm., 

 smooth, and indented by developing calicles. The epitheea leaves the greater part of the 

 under surface of the spoon-shaped lobes free. 



Calicles about • 5 mm. in diameter, unevenly distributed, often widely scattered, on the 

 upturned slopes opening at the tips of thin nariform ridges, on the more level portions and on 

 the under surface as irregular, cylindrical protuberances, the margin of the protuberance 

 generally runnmg up on one side into separate tubercles or into fused plates. The septa in 

 two cycles, snort and stout, symmetrically arranged ; slightly thicker directives ; deep fossa ; 

 the margin of the calicle not sharply circumscribed. On the under surface, the septa are less 

 developed and the fossa is much more open ; the numerous calicles opening on the turned-up 

 imder edges of the spoon-shaped lobes are sMghtly depressed. 



Goenenchyma appears to be an open filamentous reticulum, the upper and lower surfaces 

 appearing very dense and covered with innumerable frosted granules. The tubercles, which 

 rise above the surface, are not sharply defined, but generally unite to form either hoods for the 



