218 MADREPORARIA. 
spicuous in the walls of the calicles, but not in the septa, while the trabecular elements 
become conspicuous in the size of the septal granules and pali. Both elements are 
conspicuous, without either being developed at the expense of the other. 
Similar small, constricted, squarish knobs at the tips of the branches, each consisting 
mainly of the undifferentiated, flaky, axial reticulum, are found also in P. Maldives 3. 
a. Zool. Dept. 91. 4. 9. 39. 
RODRIGUEZ. 
The following from Rodriguez, collected during the Transit of Venus expedition in 1874-75, 
were arranged by Dr. Briiggemann * under two separate species. In my judgment they 
show essentially the same type of calicle structure, with irregularly reticular walls changing 
at any moment into quite thin, straight, single threads or membranes, no traces of which are 
found as median ridges or plates when the wall becomes reticular. The growth-forms also 
show a similarity reminding us of the Ramesvaram series, here called P. Ceylon 1-8. The 
stocks grow either on the tops of other corals or on the overturned masses of their own 
previous growths, as if unable to adhere to the inorganic substratum, whatever it was. I 
have divided them into two heads. The first has very small calicles, and forms a flat cake 
on the top of a dead Astraid, traces of which can still be seen; while in the second the 
stock rises like a stalked knob from the side of the mass of its own previous growth. 
225. Porites Rodriguez 1. (P. Rodericensis prima.) (Pl. XXXII. fig. 4.) 
[ Rodriguez, coll. Transit of Venus Expedition; ft British Museum. | 
Syn. “ Porites lutea M.-E. & H.” Briiggemann, Phil. Trans. elxviii. (1879) p. 577. 
Description.—The corallum forms large round cakes, flattened on the top, and very 
smooth. The edges are closely encrusting, and here and there bending under. 
The calicles are small, under 1 mm., sub-circular, shallow, yet rather sharply sunk 
between thick walls. The walls are a rather close irregular reticulum, without trace of 
median ridge or radial symmetry; the interseptal loculi run as rough notches into the 
wall. The septa project only deep down, and are thus obscure, but a small conspicuous 
ring of five pali rises nearly to the height of the wall (formula F, fig. 3, Introduction, p. 19). 
The minute deep pin-hole fossa is visible to the naked eye. 
There is no available section. The colour is a light grey. 
* Phil. Trans., vol. elxviii. (1879) p. 577. 
} The name “Gulliver” on the label refers to one of the naturalists of the expedition, 
