﻿32 MADKEPOEARIA. 



with the fragment was dead, but was sirrrounded by a living zone about 20 cm. broad. The 

 livin" zone was apparently growing back again over the dead portion. The surface of the 

 whole is covered with recumbent worm tubes, and large and small Balanids, all of which are 

 partially imbedded in the ccenenchyma. 



a. Wednesday Island, Torres Straits H.M.S. ' Challenger.' (Type.) 



(in two pieces). 



In 1888, Dr. Ortmann described a Montipore from Samoa, in the Strassburg Museum, 

 under the name M. scahriculoides, but in 1889 he identified it with this species. 



15. Montipora glabra. (PI. XXXII. fig. 1.) 



Description. — CoraUum thin, free, horizontal, explanate, of nearly even tliickness, 3 mm., 

 at the growing edge 2 mm. Epitheca extensive, but irregular and in patches. 



Calicles uniformly small, 0'50 mm., evenly distributed, about 1 mm. apart. Septa 

 irregular, as mere pointed granules projecting over the edge of the aperture, six primaries 

 being usually distinct. The second cycle partially developed. 



Ccenenchyma in section an open, coarse reticulum, the streaming layer not very pro- 

 noimced as it bends upwards and downwards very gradually to form the upper and lower 

 surfaces. Where the lower layer rests upon the epitheca it solidifies. The upper surface is 

 porous and granular to the naked eye, but is perfectly level, i.e. without interstitial uprisings. 



There are a number of fragments of this coral from Torres Straits, which reveal nothing 

 as to the method of attachment of the stock. It is very closely allied, if it be not specifically 

 identical with M. comj^lanata ; the caUcles on Lamarck's type are perhaps more crowded and 

 the ccenenchyma coarser. Again, in general appearance, and in the fact that the streaming 

 layer in both has been attacked by a boring sponge, the coral resembles M. cxserta of Quelch, 

 which is also from the Torres Straits. But the exsert directives are so marked a feature 

 over the whole corallum in this latter type, whereas exsertness of the septa is only found in 

 single calicles, and then not very marked in the specimens under discussion, that it is better 

 to keep the two apart. Further, the corallum in M. exserta is much thicker, the upper 

 perpendiciilar layer alone being 3 to 4 mm. thick. It is, however, q\iite possible that further 

 specimens will establish the specific identity of these three forms, M. coviplanata, M. exserta, 

 and M. glabra. 



a. Torres Straits (in eight fragments). Prof. A. C. Haddon. (Type.) 



