584 COILECTIONS FROM IHE WESIEEN INBIAN OCEAN. 



Indian Ocean shaUow-water faunas, we find 16 out of the 56 spe- 

 cies obtained in the latter region to be identical with Australian 

 species, a proportion to the whole of 2 : 7, or 28 per. cent It is 

 BtiU more remaxkable to find that of these, three (viz. Oarterisponaia 

 otaUUca, lotrochota ^purpurea, Olathria frondifera) occur abun- 

 dantly m both places. Had Dr. Coppinger's researches enabled me 

 to add more species to the Ust, I have little doubt that still greater 

 proofs would have been forthcoming of a former communication 

 between these two widely remote districts. As might almost have 

 been expected 14 of these identical species occur in tropkal waters 

 in Australia also (chiefly from Torres Straits or N. Queensknd, but 

 one third of the number from Port Darwin). 



Of the mutual relations of the different localities in the district at 

 present under notice I have little to say, as the investigation of them 

 must be admitted not to be sufficient for a satisfactory comparison 

 In spite of Its muehmore westerly longitude and'of its separation 

 from the other localities by much open sea and in part by that great 

 body of land, the island of Madagascar, we find no decided differ- 

 ences between the fauna of Mozambique and that of the rest of the 

 distnct; perhaps the Mozambique current partly accounts for this 

 On the other hand, we find that 7 out of the 13 species recorded 

 from the Seychelles were not found in the other localities: probably 

 this IS partly due to the fact that here alone was dredging regularlv 

 carried out The Amirante Islands have the greatest number of 

 species (26). 



r«^owom2/.-Of the strictly taxonomical aspects of this part of 

 the collection little has to be sajd which has not been already said in 

 the Melanesian portion of this Eeport. I therefore refer those in- 

 terested m the subject to that part of the Eeport for most questions 

 relatmg to the general zoology of the Group and to the bearing of 

 these coUections on classification and morphology. The full descrin 

 tions of new species and genera which are represented also in the 

 Melanesian coUection will be found in the Eeport on that coUection • 

 they are not noticed at length in this place. This coUection from 

 the Western Indian Ocean is remarkable for the large nronortior! 

 (31 per cent, of the whole) which the Ceratose spongS bea? o he 

 remaimng groups : this is no doubt largely due to the number of 

 "beach specimens ' included m the collection, representing, as such 

 specimens naturaUy would, most chiefly this less perishab e order 

 This proportion probably more closely resembles that which would 

 be obtained m the South-west of Australia than that found bTthe 

 'Alert' in the Eastern and Northern parts of that continent (wh ch 

 was about 18 percent.); but the species are smaller than the ge^. 

 rahty of those which contribute so largely to the Rhnr« o-a+i, • 

 at Freomantle, West Australia. ^ ^ '^""^^ gathejings 



No specif of the order CTemtos call for special notice here. 



Oi the MmachneUidSthcea Time of the PamiHes are stron-lv re- 

 presented, the Eeniendec, with 7 species, being the most abundant 

 and yet mamtammg only about the same proportion (15 per centTto 

 the remainder of the Sponges as in tL Melanesian^ Xctin 



