L>1 



1910.] ON HTDR0ID3 FROM MERGUI ARCHIPELAGO. 799 



[^From the PROCEEBIJfGS OF THE ZoOLOGIOAi SOCIETY OF LONDON, 



1910.] 



rpubiigijed October 1910.] 



Tlie Marine Fauna of the Mergui Archipelago, Lower 

 Burma, collected by Jas. J. Simpson, M.A., B.Sc, and 

 R. N. Rudmose-Brown, D.Sc, University of Aberdeen, 

 February to May 1907. — The Hydroids. By James 

 Ritchie, M.A., B.Sc, Natural History Department, The 

 Royal Scottish Museum *. 



(Plates LXXVI. k LXXVII.t, and Test-fig. 79.) 



The Hydroids were reprosented in the collections brought 

 together in the Mergui Archipelago by Dr. John Anderson in 

 1882, and described in the Journal of tlie Linnean Society for 1889, 

 by a meagre total of six species, two of which were regarded by 

 Hincks as new. The reasonable anticipation that tiie careful 

 collecting of Dr. Brown and Mr. Simpson would add many species 

 to the Hydroid fauna of this region of the Indian Ocean has been 

 amply fulfilled ; for the present collection, confined to a littoral 

 area, contains representatives of thirty species, only three of which 

 {Campanidaria raridentata and Idia prisiis, both widely distriljuted 

 species, and Aglaophenia crispata, a synonym of Lytocarpus pen- 

 7iarius,Jide Billard, 1909, p. 329) were included in llincks's list. 



As only two of the species, being described as new to science, 

 must be regarded as peculiar to the Archipelago, the collection is 

 well fitted to show the relationship which the Hydroid fauna 

 bears to that of neighbouring seas. Leaving out of account 

 an luidetermined species of Plumidaria, nineteen of tlie Mei-gui 

 species have already been recorded from the Indian Ocean, 

 the majority of these occurring oil' Madagascar anil tlie eastern 

 shores of Africa. The remaining ten species, indicated by 



• Communicated by R. KiKErATRtCE, F.Z.S. 

 + For explanation of the I'lates sec p. B25. 



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