﻿82 MADREPOEAEIA. 



tion is physiologically correlated with the thinness of the horizontally growing coraUum, and is 

 not developed in thicker and older stocks or when not required. 



c. Macclesfield Bank, China Seas, Coll. Bassett-Smith. 



25-30 fathoms. 

 d. Macclesfield Bank, China Seas. H.M.S. ' Eambler.' 



Two other specimens, which are perhaps varieties, also belong here. They are small, thin, 

 nearly circular plates, very disfigured by Balanids, growing horizontally, one growth covering 

 up another. Wherever the surface is free from encrusting calcareous algte, tubicolous worms, 

 or Balanids, it is a mass of warts of all sizes, many being smooth, round, dome-shaped. 

 The larger and more irregular warts, on close inspection, are young Balanids very nearly or 

 quite covered over and killed by the coenenchyma. Hardly any calicles are visible when the 

 coral is searched from above. Directly it is looked at sideways from the growing edge fairly 

 conspicuous calicles, like those of the type, are seen on the faces of the dome-shaped papillae. 



c,f. Macclesfield Bank, China Seas, Coll. Bassett-Smith. 



28 fathoms. 



62. Montipora guppyi. (PI. XV. ; PI. XXXIII. fig. 5.) 



Description. — Corallum explanate, as a large, nearly flat, expanding frond, with lateral 

 edges irregularly reilexed, and attached by a thick narrow stalk. The growing edge is thin 

 and sharp, under 2 mm., the stalk being about 1 cm. thick. An epitheca follows about 

 6 cm. behind the distal growing edge, and about 3 cm. from the lateral crumpled edges of 

 the frond. 



Calicles distinct, large and open, about 1 mm. diameter, irregularly crowded, mostly less 

 than one diameter apart, hardly visible on the smooth surface close to the growing edge, but 

 gradually, at 1 cm. from the edge, become hooded over by uprisings of the coenenchyma, the 

 aperture tilting but very slightly outwards. Six primaries weU developed, reaching to the half- 

 radius circle, secondaries slight, here and there ; the interseptal loculi are sharply cut out of 

 the flakes of the reticulum, and when secondaries are indicated, are heart-shaped. On the 

 under surface, the calicles are very inconspicuous and are less crowded, about • 5 mm. aperture, 

 and open on the smooth but slightly pitted reticulum. 



Coenenchyma. The typical layers of the section are obscured, the whole being a coarse 

 reticulum which becomes denser as it recedes from the thin, reticular growing edges. In surface 

 texture it appears as if consisting (in the older portion of the colony) of glistening flakes and 

 granules, the latter being jagged and twisted in all directions, throwing up fine points. The 

 tendency to rise behind the calicles becomes more pronounced, the further one goes from the 

 edge, tiQ the whole surface is covered with papillEe, on the distal faces of which, low down 

 near their bases, calicles open. The originally hood-like papiUce, by increasing in size, 

 often carry up neighbouring calicles also which had no hoods, so that in the older parts 



