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Show 1900.] MARINE FAUNA OF CHRISTMAS ISLAND. 127 easily have, as some variation in their thickness is observable dried specimens. Pools on reef-flat, Flying Fish Cove. Genus AGARICIA Lamarck. There is a fragment of what appears to be a flat incrusting 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,finely 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 in 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. Bock-pools under cliffs S. of Flying Fish Cove. IV. On the Sponges of Christmas Island. By B. KIRKPATRICK. 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 (Pachychalina spinosissima 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 CARNOSA. 3. Chondrosia reniformis Nardo. 4. Chondrosia plebeja 0. Schmidt. 5. Chondrilla nuda Lendenfeld. |