﻿PAPILLATE MONTIPOR^. 85 



of Ehrenberg's type specimen, which is 10 cm. high and 15 cm. broad. The description 

 makes it clear that the ccenenchymatous elevations are, as in the case of M. gradlis, simply 

 the swollen under margins of the calicles. Proliferations of these under lips may give rise 

 to small cylindrical twigs covered with calicles. Klunzinger remarks that this type is very 

 similar to Ehrenberg's circiimvallata (also from the Eed Sea). In view of the very similar 

 specialisations of the coenenchyma, I think it highly probable that the two are really 

 specifically identical. 



The specimens in the National Collection which agree closest with this description are 

 two from the Persian Gulf. One specimen shows the cockscomb-like upgrowths springing 

 at right angles from a lateral expansion of an encrusting plate. On to this encrusting mass 

 the other specimen, which forms a thick, roughly speaking globular tuft of fused branches, 

 exactly fits. The two specimens thus really belong to one and the same stock. 



The stock, studied as a whole, forms an irregular platform across the tips of other 

 branched corals, the corroded remains of which can still be seen. From this platform the 

 coral rises in tufts, each tuft apparently starting as a long, narrow ridge. One such tuft 

 (specimen b) 10 cm. high and 10 in diameter, rises from a narrow ridge-like base 3 cm. long 

 and varying from 1 to • 5 cm. broad ; while a little way off another such ridge is begin- 

 ning to rise as a thin cockscomb,, the sides and edge of which are commencing to put out 

 twigs. The developed tuft (&). is a compact mass of flat ridged plates, and thin fringe-like 

 twigs often fused side by side. At a height of 6 cm. a deposit of sediment seems to have 

 caused the tuft to form another partial platform. 



The specialisation of the coenenchyma is that of the type. On the thin, cylindrical 

 twigs, however, the calicles are so crowded that the protuberant lower margin of one forms 

 the upper margin of that next below, so that to all appearance the calicles are walled 

 around (cf. M. circumvallata which is said to differ from crista-galli in the very fact that the 

 calicles are walled round). We see hwe that this distinction is of very little value, the 

 variation depending entirely upon the distribution of the calicles. 



On the fine series of Montipores in the Paris Museum, identified, with Ehrenberg's type, 

 see Montipora JEdwardsi, p. 78. 



a, h. (Fitting together to form one stock) A. S. G-. Jayakar, Esq. 



Persian Gulf 



65. Montipora gracilis.. 



Montipora gracilis, Klunzinger, Korallenthiere des Eothen Meeres, ii. (1879) p. 37, pi. vi. fig. 7 ; 

 pi. v. fig. 12; pi. X. fig. 9. 



Description. — Corallum small, stunted, forming irregularly branching tufts, the ultimate 

 twigs being not unlike protuberant calicles, the whole having some resemblance to a typical 

 Madrepore. The basal portion dies away and is covered by a white film, above which the 

 living zone is about 4 cm. deep. 



Calicles minute (0 • 5 mm.) but distinct ; evenly distributed about 1 mm. apart. Septa in 

 two cycles, very irregularly developed as short thick granules projecting from the surface 



