1022 MISS R. HARRISON AND PROF. S. J. HICKSON ON 



Edwards & Haime [23] as lleterocyathus ceqiticostatus ; to this 

 Bourne [6] lias since added Steplianoseris rousseaui. 



In the large collection of corals from S. Africa, Gardiner 

 recognized two types with the following diagnostic characters : — 

 Type I. Costte equal in size, rounded and covei-ed with low 

 granules (PI. LYIII. fig. 12), small intercostal spaces ; base smooth, 

 low granules, only traces of costal ; theca with thin upper edge, 

 never more than 1 mm. above columella ; septa in four cycles, 

 thick with narrow interseptal spaces, average exsertness 1*5 mm. ; 

 cycle i. broader and more exsert than cycle ii., ii. than iii., iv. 

 more exsert than iii., higher on either side of i. than of ii. Sides set 

 with low ridges, edges not toothed ; commonly certain ones, or all, 

 coloured black ; pali before all cycles, large and conspicuous ; 

 columella a mass of rods decreasing in size and height from 

 the pali towards the centre of the axial fossa, densely packed 

 together. 



Type II. Cost?e of cycles i., ii., and iii. larger than iv., which 

 consists of a row of separate granules rougher and higher than in 

 Type I, with broader intercostal spaces (PL LVIII. fig. 13) ; base 

 roughly granulai', costee sometimes extending on to it ; theca with 

 thin upper edge, generally 2 to 3 mm. above the top of the 

 columella ; septa in four cycles with a tendency to have some of 

 a fifth cycle represented, thin with broad interseptal spaces, 

 average exsertness 3 mm. ; ridges on sides conspicuous, edges 

 toothed towards centi-e of calice ; all the same colour, white or 

 some shade of grey ; no proper pali or columella ; septa iv. fuse 

 with septa iii., and these again with ii, ; septa i. generally separate, 

 but in the centre fuse with the rest forming a mass of trabeculte 

 covered by fine points which run up along the septa of cycles i. to 

 iii. for some distance, almost like fine teeth. 



In describing the collection of Mr. J. J. Simpson and 

 Dr. Rudmose-Brown from Burma, Miss Poole [24] recognized 

 the Gardiner's two types, and added a third type with a fifth 

 cycle of septa, four ciowns of nodular pali, and a deeper fossa. 



I have been able to re-examine the collections described 

 by Professor Gai-diner and Miss Poole, and, so far as the former 

 collection is concerned, the two types are sufficiently difi'erent, 

 in my opinion, to be regarded as two species. Gardiner himself 

 has. described them as " two perfectly distinct modes of growth, 

 almost two varieties." I have searched in vain for intermediates, 

 and although I had no difficulty in picking out the two specimens 

 which the author describes as doubtful, they are both too much 

 broken and corroded to afford any clear evidence that they 

 represent a form intermediate between the two types. The 

 general facies are entirely diflferent. In Type I, the tendency is 

 for the base to be broader than the calice in correlation wdth 

 rounded granular costfe, thick septa, practically no fossa, and a 

 papilliform well-developed columella. In Type II, the tendency 

 is for the coral to taper away to a point from a circular calice ; 

 such is the form of the only known example without a commensal 



