1910.] t)x iiybroids from mergui ahciiipelago. 799 



Bibliography. 



1. Collin, A. — " Rotatorien, Gastrotrichen iind Eutozoen O.st- 



Afrikas." Deiitsch-Ost-Afrika, 189G, vol. iv. no. 16. 



2. Daday, Prof. E. von. — " Plancton-Tiere aus clem Victoria 



%anza." Zool. Jahrbiicher, Kd. 25, 1907, pp. 245-262. 



3. RoussELEX, C. F.— -" Contribution to our Knowledge of tiie 



Rotifera of South Africa." Journ. Royal Micr, Soc. 1906, 

 pp. 393-414. 



EXPLANATION OP PLATE LXXV. 



Fig. 1. Nofops Jofaana Roui=!selot, dori5al vitnv. X 300. 



2. „ „ „ latc-ral view. X 300. 



3. „ „ „ the jaws. X alwut 700. 



3. The Marine Fauna o£ the Mergui Archipelago, Lower 

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

 R. N. Hudniose-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 *. 



[Received April 28, 1910.] 

 (Plates LXXVL t LXXVII.t, and Text-fig. 79.) 



The Hydroids were rei^resented in the collections brought 

 together in the Mergui Archipelago bv Dr. John Anderson in 

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

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

 Hincks as new. The reasonable anticipation that the careful 

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

 to the Hydroid fnuna 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 

 {CamjJanidca'iararidentata and Idiajiristis, both widely distributed 

 species, and Aglaoj^henia crisjmta, a synonym of Lytocarpus ^?eji- 

 narius,fide Billard, 1909, p. 329) were included in Hincks'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 neigh homing seas. Leaving out of account 

 an l^ndeterrained species of Plumularia, nineteen of the Mergui 

 species have already been recorded from the Indian Ocean, 

 the majority of these occurring oft" Madagascar and the eastei'n 

 shores of Africa. The remaining ten species, indicated by 



* C'ouiuiuiiieateil liy R. Ktrkpateick, F.Z.S. 

 t Eov explanation of the Plate; see p. 825. 



