108 CEYLON PEARL OYSTER REPORT. 



several distinct localities and in great abundance, while other species are represented 

 by one colony each. From the large number of specimens obtained, and the manner 

 in which the colonies are crowded together on the foreign bodies to which they are 

 attached, it may be inferred that the Ceylon seas are a favourable locality for the 

 Polyzoa ; but at the same time, from the multiplication of avicularia and of spinous 

 processes of various sorts which characterise these Ceylonese specimens, the impression 

 is derived that there is severe competition and that the colonies have a struggle to 

 hold their own. It is possible that the avicularia, spines and other roughnesses on the 

 surface of the zoarium may protect such species from being smothei'ed by overgrowths 

 of colonies of their own kind ; and this seems a very necessary protection in this 

 case, and the need may account for some of the extraordinary calcareous outgrowths 

 of the zocecia which I have to describe below. 



Comparatively few collections of Polyzoa have been made in Indian seas. Hincks 

 (16) reported in 1887 upon a collection made by Dr. Anderson in the Mergui 

 Archipelago. Kirkpatrick (22) described in ] 895 a collection made by Mr. Thurston 

 in the Gulf of Manaar. Among Hincks's series of papers, entitled " Contributions 

 towards a History of the Marine Polyzoa," in the ' Annals and Magazine of Natural 

 History ' (8), there is a report upon a small collection from Indian seas, and here and 

 there among other papers of this series may be found descriptions of a specimen or 

 two from Ceylon. In all, perhaps, 45 species have been previously described from 

 the seas around Ceylon. Of these, 31 are represented in the present collection ; and 

 85 additional species, including 16 new to science, are now recorded for the first time. 



The work has been carried out chiefly in Liverpool, but it is a pleasure to record 

 the help that has been freely given to me in Cambridge and in London. Dr. S. F. 

 Harmer has kindly allowed me to consult his private collections of specimens and 

 notes, and Mr. P. Kirkpatrick has helped me with those at the British Museum ; to 

 both gentlemen I am indebted for advice, and suggestions. In conclusion, I should 

 like to express my gratitude to Professor Herdman for the privilege of being allowed 

 to handle and name his valuable collection of Polyzoa. 



Order: ECTOPROCTA. 



Sub-order : CHEILOSTOMATA. 



Family: .ETEID/E. 

 JEtea anguina, Linn. 



Localities: Station I., off Negombo, 12 to 20 fathoms; and Station XLVI., off 

 Mount Lavinia, 7 to 12 fathoms. 



Family: CATENARIID/E. 

 Catenaria lafontii (Auu). 



Locality: North of Cheval Paar, 7 to 10 fathoms. 



