778 J. STANLEY GARDINER. 



pressing over one another, to the last belonging the round form which in this respect is 

 exactly as described by Klunzinger for L. inequalis. The calices of flat specimens and of 

 the round one average 25 mm. in diameter, or somewhat more hilly 3'5 mm., the living 

 edge of a once large mass 4 mm. ; here and there a giant calice may be found, one rather 

 rough specimen with low calices averaging 3 mm. having a number of these standing up 

 for 2 or 3 mm. and being 4'5 — 6 mm. in diameter'. The costae may be distinct or not 

 visible, distance between the calices '5 — 2 mm. or more, especially on the under side. Septa 

 rough or quite smooth, in giant calices 38 — 40 down to 20 in the smaller ones, very rough 

 sided or almost smooth ; in the round and most forms with larger calices, cycles I. and II. 

 quite equal, or in many of the smaller caliced flat forms I. distinctly larger than II. Columella 

 well developed or scarcely visible, in some cases in surface view clearly formed by trabeculae 

 which end above in fine points, in others like the end of a bundle of thick rods, formed 

 from 12 septa or more in the first case (round and most forms) and from 10, 8 or even 6 

 (one sjjecimen) in the flat forms. 



Locality. Common on the reef-flat at Minikoi and throughout the Maldives, rare on 

 lagoon reefs. Colour, a dark but brilliant green. 



XV. Genus Gyphastraea. 



Cyphastraea and Solenastraea Ed. and H., Gyphastraea Klunzinger. 



The growth of the genus is mainly incrusting, though it frequently attains a thickness - 

 of several inches to a foot. It closely follows any inequalities on its base of attachment, 

 and tends, if it gets free, to round itself off and become completely covered with polj'ps. 

 More massive growths on any colony may rise into hillocks, which themselves frequently 

 become rounded off. The corallum below the living tissue forms a home for all sorts of 

 boring animals, and tends to become much broken up and hollowed even to within 3 or 

 4 mm. of the living polyps. 



Distribution. Occasionally found incrusting on the reef-flat, or breaker-zone, or on 

 lagoon shoals : free masses in protected situations of the same, but never on sand. Depth, 

 to 40/ Colour, grey-green. 



43. Gyphastraea forskaelana (Ed. and H.). Ed. and H., ii. p. 497. 



Two colonies, both of which form masses nuich bored into and killed at the base, and 

 covered with convexities and humps, not free. The calices (2 mm. in diameter) are thick 

 edged and crowded together except underneath and near the edges of the colonies, rounded, 

 not distorted, commonly projecting for at least 1 mm. Exotheca appearing vesicular from the 

 surface, fairly dense in section, with a few, rough, pointed spinules, generally clearly connected 

 with the costae, which are little prominent and very rough, varying up to 24 in number. 

 Septa little exsert, sides covered with low, rough spinules, scarcely toothed, systems and 

 cycles quite distinct, primaries much more prominent and rougher, running right into a well- 

 developed, rather shallow, finely trabecular columella. Secondaries commonly much thinner, 

 and occasionally simulating the primaries and fusing with the columella, especially near the 

 edges, where the calices are more distant. Tertiaries very small. 



' Cp. Prof. Bell's description of Variation in Turbinaria, Quar. Jour. Micros. Soc, 1895, p. 148, pi. 1 and 2. 



