﻿TUBERCULATE MONTIPOR^. 121 



98. Montipora inconspicua. 



Description. — Corallum forms minute, encrusting patches, 2 to 3 mm. thick. Free edges 

 are contained in a well developed, wrinkled epitheca which curls upwards. 



Calicles 0'5 mm., 1*5 to 2-0 mm. apart, very inconspicuous, fossa nearly filled up with 

 two cycles of septa. Primaries thick, not exsert, nearly reaching to the centre ; secondaries 

 thin and half as long as primaries, often irregular. 



Coenenchyma, character in section not shown. Surface thickly covered with minute 

 round tubercles, just distinguishable above the surface yet quite distinct from one another, 

 like minute woolly spheres without sharp outlines. Those round the calicles are slightly 

 more developed, but all are so low that the calicles appear hardly at all immersed. 



The single specimen of this tuberculate Montipore occurs in two small patches struggling 

 for existence with the more vigorously growing stock of M. holsii (see p. 34). It is tlius one 

 of the explanate Montiporans which, with M. holsii and M. exigua, form the laminated crust 

 mentioned in the descriptions of those corals. All three of them have remarkable superficial 

 resemblances. The differences, as seen under a pocket lens, necessitate their being described 

 under different headings. Both the small patches of this minute tuberculate coral are being 

 gradually arched over by free edges of the larger M. holsii. 



a. (With M. holsii) Billiton. CoU. Bolsius. 83. 7. 24. 103. (Type.) 



99. Montipora challengeri. (PL XXII. fig. 1 ; PL XXXIII. fig. 17.) ' 



Montipora effusa, Quelch (non Dana, nee Milne-Edwards and Haime), Chal. Rep., Reef Corals (1886) 

 p. 178. 



Description. — Corallum thin and explanate, horizontal, slightly dish-shaped, attached by 

 one side, surface uneven, irregularly translucent, the edge closely reflexed for about one centi- 

 metre ; 2 mm. thick at growing margin, 5 mm. near centre. The epitheca well developed, 

 wrinkled, runs everywhere under the reflexed margin, bends out over it and may overlap it, 

 with here and there a second incipient reflexion. 



Calicles inconspicuous, minute, less than • 5 mm., scattered, appearing in two forms at 

 the surface. Those which open on the level portions of the corallum are immersed and irregular, 

 and generally have few septa at the aperture, which is not sharply circumscribed ; only when 

 held up against the light do the typical six primaries appear, with secondaries all very 

 irregularly developed. Those calicles which are surrounded by small groups of tubercles 

 show the typical radiate character at the surface, but are very irregular in shape. On the 

 reflexed under surface the star-like calicles are immersed in a coarse open reticulum with 

 which their borders are in sharp contrast. 



The coenenchyma consists in section of a laminate streaming layer in close contact witli 



s 



