SPONGES. 235 



It appears from the above list that no less than 215 species of sponges (including 

 about seven doubtful ones) have now been recorded from Ceylon waters, which evidently 

 form an extremely rich centre of sponge distribution. Of these 215 species, 146 

 occur in Professor Herdman's collection, of which 77 (or 527 per cent.) are here 

 described as new. 1 consider it very satisfactory to have been able to identify as 

 many as 69 previously known species in the collection, especially as I always prefer 

 giving a new specific name to making a doubtful identification ; mistakes of the latter 

 kind being often far more difficult to coi-rect than those of the former. Seventy-five 

 out of the total number of species have been recorded from localities beyond the 

 Ceylon area. 



As regards the general character of the Ceylon Sponge-Fauna, the most striking 

 feature, next to its richness, is its close relationship with the Sponge-Fauna of 

 Australia and the adjacent islands. In the Report on the " Challenger" Monaxonida 

 we defined an area of distribution (No. IV. on the chart) including Australia and the 

 islands north of Australia as far as the Philippines (inclusive). This we called the 

 Indo- Australian area. No less than 47 out of the 75 species whose range is known to 

 extend beyond the Ceylon region are common to the latter and our Indo- Australian 

 region the majority of them occurring actually along the Australian Coast. 



Of these 47 species, the following are not known to occur except in the Indo- 

 Australian area (in the "Challenger" sense) and westwards as far as Southern India: 

 Stceba simplex, Myriastra clavosa, Pilochrota haeckeli, Geodia globostellifera, 

 Xenospongia patelliformis, Chondrilla australiensis, Toxochalina robusta, Reniera 

 madrepora, Petrosia testudinaria, Chalina sub-armigera, Siphonochalina communis, 

 Esperella parishii, (?) Iotrochota purpurea, Histoderma fistulatum, Leucophlceus 

 fetid us, Hippospongia anomala, Hircinia vallata, LeuciUa cucumis. The following 

 extend (so far as known) westwards not further than the East Coast of Africa 

 or eastwards not further than New Zealand : SpirastreUa vagabunda (Aden), 

 Ceraochalina multiformis (New Zealand), Iotrochota baculifera (Western Indian 

 Ocean), Clathria frondifera (Western Indian Ocean, Red Sea), Acarnus ternatus 

 (Western Indian Ocean, Tahiti), Ciocalypta tyJeri (Port Elizabeth), Psammopemma 

 crassum (New Zealand), Phyllospongia papijracea (Mozambique, Australia ?, New 

 Zealand ?), Aplysina fusca (Seychelles), Leucosolenia darwini (Pted Sea), Leucandra 

 pulvincvr (lied Sea). Another characteristic Indo -Australian species is Agelas 

 mauritiana, hitherto recorded only from Mauritius, Ceylon, Ternate (under the 

 synonym A. cavernosa, Thiele), and doubtfully from Tristan da Cunha. 



If, on the other hand, we compare the Ceylon Sponge-Fauna with that of the Pted 

 Sea, as elaborated chiefly by Keller (61), we notice a considerable difference. 

 Kellek records a total of 88 species from the Red Sea, to which Topsent (91, 92) 

 has added 13. Of these, only 14 are known to occur in Ceylon, viz. : Spongelia 

 fragilis, Euspongia officinalis, Cacospongia cavernosa, Hippospongia claihrata, 

 Clathria frondifera, Acanthella flabelliformis, SpirastreUa vagabunda, Placospongia 



2 H 2 



