126 MB. 0. W. ANDREWS AND OTHERS ON THE [Feb. 20, 



dry specimen the adjoining calicles, or rather troughs, are closely 

 adherent ; the exsert septa almost overlap in the larger spirit- 

 specimen (6 cm. long), in which the skeleton is obscured by the 

 soft parts ; the ridge between the calicles appears to widen here 

 and there into an ambulacrum from 1-2 mm. wide. The calicular 

 trough must have been 3 cm. deep and as much across, while the 

 primary septa are very stout and exsert, and with their inner 

 edges rather more vertical than in Mitssa regalis, at least near the 

 top of .the ridge. The soft parts are bright green. Small cup- 

 shaped galls are found on the septa here and there, somewhat like 

 those occurring on the specimen of Coeloria (see below). 



Occurs on the sides of the deep channels at the rim of the reef. 



Genus Leptoria M.-E. & H. 



Leptoria phrygia Ellis. 



Leptoria phrygia Ellis, Zooph. p. 162, 1786, pi. 48. 



One fragment from a massive growth. It shows both straight 

 and gyrating calicular troughs. A good section shows the thick 

 plate-like columella with its lobed and also finely serrated edge. 



The species is said to extend over the Indo-Pacific area. Dana 

 records it from Ceylon. 



Pools on reef-flat, Plying Fish Cove. 



Genus Cceloria M.-E. & H. 



C(ELORIA SINENSIS M.-E. & H. 



Coeloria sinensis M.-E & H. Les Cor. ii. 1857, p. 416. 



One large specimen which agrees in all important points with 

 this species. The Chinese type had calicular troughs not exceeding 

 2 cm. The specimen from Christmas Island has the same 

 tendency to short troughs, some being round and only a few mm. 

 in diameter, but a few reach to 3 and 4 cm. in length. What 

 appear to be galls occur on the septa here and there. 



Pools on reef-flat, Plying Pish Cove. 



Genus Prionastrjea M.-E. & H. 



PrIONASTR.EA AUSTRALENSIS M.-E. & H. 



Prionastrcea australensis M.-E. & H. Les Cor. ii. 1857, p. 520. 



There is a narrow convex strip with the angular surface charac- 

 teristic of this genus. It may provisionally be placed near 

 P. australensis, with which it agrees in size of calicle, thin walls, 

 and rudimentary columella ; while round the columella a ring, 

 often incomplete, of larger septal teeth rises up, either 2-3 on each 

 septum, or else one large paliform tooth. 



There is further a very similar specimen in spirit of the same 

 bright green which seems common to these Christmas Island 

 Madreporaria. It appears to have much thicker walls than the 

 dried specimen, but the presence of the soft parts would at least 

 partly account for this. Slightly thicker skeletal walls it may 



