INDIAN OCEAN GONIOPORA. 91 



Calicles over the general surface (fig. 8) small, 2 mm., polygonal, open, uniformly shallow 

 ca. 1 mm., with low thick walls consisting of a frosted zigzag thread. The wall is thickened 

 on each side hy short closely packed frosted septa, and frequently appears as if striated 

 across the top. The union of these septa by additional synapticulse frequently makes the wall 

 a close reticulum. The septa are thick and granulated and finely frosted, and show the 

 typical formula with the usual two rows of pali, as large frosted granules rising at the points 

 of fusion. Seen sideways the six large pali rise like clubs not quite as high as the wall. 

 Small granules sometimes rise from the ends of the directives. The columellar tangle is 

 inconspicuous and somewhat obscured by the ring of pali. The interseptal loculi are 

 inconspicuous. 



The texture is altered on the tips of the knobs (fig. 7), being there a thin filamentous 

 reticulum with a corresponding diminution in thickness of the intracalicular skeleton and 

 increased size of the interseptal loculi. 



There is only one large very irregular specimen, 25 to 30 cm. high by 30 cm. across (see 

 PL XIII. fig. 10), growing over several generations of previous growths. It is covered with 

 columns and it is a question as to how far these were originally started by irregularities of the 

 substratum, or are a normal growth. If the latter, they are quite peculiar within this genus. 

 In Montipora, in which there is a special development of the ccenenchyma (see Vol. III.) it is 

 common to find explanate stocks from the surface of which vertical columns arise. Contrast 

 this with the tuft formation found in Goniopora, also derived from explanate stocks, but by 

 the turning up and curling of the edges, see G. Great Barrier Reef 12. 



The specimen is entangled with a great mass of calcareous alga and perhaps thereby 

 distorted. Here we have another instance of an explanate Goniopora with the regular calicles 

 typical of that growth-form, cf. Introduction, p. 25, and figs. 8, PL VII. and 1, PL II. 



a. Zool. Dept. 83. 7. 27. 14. 



b. (A small fragment.) 



61. Goniopora Seychelles (xjL. 

 [Seychelles ; Paris Museum.] 

 Goniopora Savignyi, Milne-Edwards (partim), Hist. Nat. Coralliaires, iii. (1860) p. 191. 



Description. — Corallum forms large expanding but compact clusters of round-topped 

 smooth-sided columns, with deep chasms between, and of all sizes, some small, some very 

 thick, reaching mostly to the same general level. The living layer is only 3-4 cm. deep 

 in the central columns, but 16-17 deep on the outer sides of the outermost columns. 



The calicles are from 2-3 mm., and are more open and lamellate on the top, shallower and 

 with irregular pali at the sides. 



This imperfect description is taken from a sketch and a few pencil notes made in 

 Paris. There were two specimens; the smaller was apparently only a large detached 



N 2 



