;>2 



SPONGIIDA. 



BY 



STUART 0. RIDLEY. 



The collections of Sponges made during the latter part of the ' Alert's ' 

 voyage, although not so important from the number of species or 

 the interest attaching to the new forms as those made in Aus- 

 tralian waters, constitute nevertheless, considering the extent to 

 which these waters have been the subject of previous investigations 

 (see Introduction to Melanesian Report, p. 371) and the somewhat 

 less favourable circumstances under which Dr. Coppinger carried on 

 his collecting, an invaluable contribution to our knowledge of the 

 Spongiida of the Indian Ocean. On the latter poiut Dr. Coppinger, 

 in a letter dated Sheerness, Sept. 11, 1882, says : — " The latter part 

 of the ' Alert's ' commission has been devoted to a hurried survey 



of the Amirante Islands and of two other small groups The 



time at our disposal has been so short that we have had compara- 

 tively few opportunities of doing anything in the way of dredging. 

 What little has been done in the localities has been accomplished 

 from the ship itself, by laying out a dredge from the stern at every 

 anchorage and giving it the benefit of the swing of the ship. At 

 Seychelles, where we stopped to take in coals &c, we dredged several 

 times from the boats ; but at all the other stations our dredging- 

 operations have been limited to the swing of the ship about her 

 anchor. I mention this to account for the scantiness of the collec- 

 tion of dredged specimens from a region whose fauna is undoubtedly 

 so rich. I have, however, had plenty of occupation for my spare 

 time in exploring the beaches and reefs at times of low water, and 

 have therefore been able to accumulate a good number of marine 

 specimens from between tide-marks." In spite of difficulties, Dr. Cop- 

 pinger sent 56 species belonging to this group, including 21 species 

 not previously distinguished by naturalists. Many of the species are 

 represented by fine series from various localities : and fortunately the 

 genus Carterispongia, hitherto so imperfectly known, comes under 

 this category, furnishing a most important contribution to the 

 material available for the distinction of its species, and for the study 

 of the interesting question of polymorphism of Sponges, so well 

 illustrated by this genus. 



Distribution. — This is perhaps the most important aspect under 

 which this Collection is to be regarded. I have arranged the localities 

 for convenience under five heads, viz.: — 1. Mozambique Island (as 



