1900.] MAEIBfB FAUNA OF CHRISTMAS ISLAND. 127 



easily have, as some variation in their thickness is observable in the 

 dried specimens. 



Pools on reef-flat, Flying Fish Cove. 



Genus Agaeicia Lamarck. 



There is a fragment of what appears to be a flat incruating disc 

 with sharp free edges, the epitheca following about 1 cm. behind. 

 The very young calicles are confluent in concentric rows but soon 

 separate off, the smooth low rounded walls, tinely striated by the septa, 

 rapidly forming an irregular network over the surface; the calicles 

 all look upwards, and are not tilted to look towards the growing 

 edge. There are 4 cycles of septa — and if any columella, only iu 

 the deep calicles in the thicker parts of the stock. The section is 

 very dense, the septa being thick and closely packed with traces of 

 synapticular junctions. 



Eock-pools under cliffs S. of Flying Fish Cove. 



IV. On the Sponges of Christmas Island. By E. Kirkpateick. 



The Sponges collected by Mr. Andrews were obtained from an 

 area limited to the reefs of Flying Fish Cove. The majority of 

 the specimens were found growing on the under surface of large 

 coral blocks lying in pools left by the tide. The use of the dredge 

 was impossible owing to the irregular rocky nature of the bottom. 



Hitherto only one species (PachychaUna sjnnosissima Dendy, 

 P. Z. S. 1887, p. 524) has been obtained from this locality. The 

 present collection of 53 specimens, referable to 24 genera and 

 32 species, contains examples of 7 new species and 2 new varieties. 



The Calcarea and Monoceratina are each only represented by 

 two small specimens. 



The Carnosa are represented by three species, the occurrence of 

 Chondrosia plebeja Schmidt, recorded for the first time from the 

 Indo-Pacific, being specially interesting. 



The sponge-fauna of Christmas Island, so far as known at 

 present, is very similar to that of Java. 



A list of species, arranged according to the classification of 

 Topsent, is given below. 



Sub-Class CALCAEEA. 



1. Clathrina primordialis (Haeckel). 



2. Leucandra sp. 



Sub-Class DESMOSPONGIDA. 

 Order Cabnosa, 



3. Chondrosia reniformis JS'ardo. 



4. Chondrosia plebeja O. Schmidt. 



5. Chondrilla nuda Lendenfeld. 



