170 MADREPORAKIA. 



it appear cunipleter. Time will doubtless add to the number of the headings, and diminish the 

 number of records whose places cannot be fixed. 



The divisions in the following Table are based upon a somewhat more detailed analysis of 

 the growth-forms than that given in the Introduction. 



A. Plano-convex. 



This is the primitive growth-form of Goniopora. It is open to question how far this 

 simplest of all growth-forms persisted as the definitive shape of adult colonies ; in individual 

 cases it is impossible to say whether the specimen is not merely an earlier stage in the 

 development of some other form. Nevertheless, certain fossil Gonioporw are only known 

 with this shape of colony, and we assume that in these cases it was deiinitive. Cf. the 

 lowest colony in Diagram A, p. 24. 



G. Sind 1. 



G. Sind a. 



G. Sind 3, with irregular outline. " 



G. Ecjypt 3. 



G. Vicenza 11. 



The following four belong to the Paris Basin group where, probably owing to the 

 unfavourable conditions, e.g. the presence of sand, most of the form.s remained small. In these 

 the primitive growth-form was frequently modified by having to encrust small fragments of 

 shells, and even apparently to wrap round the stems of weeds. 

 G. Parifi Basin 1, described as hemispherical. 



G. Parift Basin 4. This apparently encircled the perishable stems of Algse. 

 G. Paris Basin 14- Apparently a normal growth which was being kUled down by 



pai'tial submergence in sand. Its tip seems as if starting a fresh growth. 

 G. Coutances il. Probably distorted by encrusting small foreign bodies. 

 Doubtful — probably young growth-stages : — 

 G. North- West Australia 4- 

 G. Verona !2. 

 G. Vienna Basin 2. 



B. Hemispherical. 



This is the simplest variation on the primitive Plano-convex, and due to an increased 

 growth in height of the calicle walls. Diagram B, p. 24. 

 G. Great Barrier Beef 6. 

 G. Java Sea 1. 

 G. Maldives 4- 

 Goniopora xa. 



The Hemispherical passes easily (a) l^y rapid growth of the central calicles into the 

 columnar ; (h) by rapid growth of all the calicles, even those round the edges, into the massive 

 globular or massive and irregular. There will always therefore be a number of specimens 

 which seem to be hovering between these different phases, and which have to be assigned 

 places provisionally. 



