MADREPORARIA WHITELEGGE. 367 



The surface echinulae consist of short bluntish spines, bearing a 

 number of ill-defined granules. 



PORITES CBASSA, Quelch. 



Porites crassa, Quelch, Chall. Rep., Zool., xvi., p. 183, pi. xi., fig. 

 2 - 2o. 



A small incrusting example of this species is in the collection. 



PORITES MIRABILIS, Quelch. 



Porites mirabilis, Quelch, Chall. Rep., Zool., p. 185, pi. xi., fig. 

 5-5a. 



There are three specimens of this rare species in the collection. 

 Of these, two are small, irregularly-convex, and incrusting ; about 

 5 cm in diameter and 2 cm. high. The third and much larger 

 specimen forms a subglobose mass with several basal expansions ; 

 the surface is somewhat uneven and gibbous. 



PORITES GAIMARDI, Edwards & Haime. 



Porites gaimardi, Edwards & Haime, Hist. Nat. Corall., iii., p. 

 179. 



There are two specimens referable to this species. The smaller 

 is subglobose, 5' 5 cm. in height and 6 '5 cm. in diameter. The 

 larger is 19 cm. long, 14'5 cm. broad, and 12 cm. high. When 

 seen in profile the shape suggests a human cranium from which 

 the facial portion has been removed. The surface is even, save 

 some superficial depressions which are present in great numbers, 

 but can only be observed when the specimen is held up towards 

 the light. 



The calicles resemble those of Porites astrceoides, Lamarck, 

 they are, however, smaller, and the walls are not so stout ; their 

 diameter is usually about 1-1 mm., rarely more but frequently 

 less. The walls are subsolid at the base, and somewhat acute at 

 the summit. 



The septa are in two cycles, thin, and somewhat ill-defined ; 

 the interseptal spaces are either circular, elongate, or keyhole 

 shaped. There are six pali, which are usually remote from the 

 centre of the calyx. Columella wide at the top, but rarely with 

 more than one granule. 



SYNAR^A UNDULATA, Klunzinger 



Synarcea undulata, Klunzinger, Die Korall. Rothen. Meeres, p. 

 48, pi. vi., fig. 12, pi. v., fig. 30. 



