particularly since it has been necessary to subject nearly the whole of it to a careful micros- 

 copical scrutiny. In a large number of cases a specimen which was placed in the collection oi 

 Polyzoa, during the original sorting of the material, has been found, on examination, to have 

 other species growing on it; and many of the most interesting specimens have been discovered 

 as the result of their occurrence on some other species which was conspicuous enough to be 

 referred to the Class under consideration. I cannot doubt that if it had been possible to examine 

 the entire collection, of animals of all kinds, many Polyzoa would have been recorded which 

 have escaped discovery. This is particularly likely to be true of the more inconspicuous forms, 

 such as Entoprocta and Ctenostomata, for instance. The genus Loxosoma, belonging to the 

 former group, is obviously very abundant in Malay waters. In other parts of the world, species 

 of Loxosoma have been found commonly on such animals as Sponges, Tunicates, Polychaets 

 and Gephyrea. Most of the specimens of Loxosoma which presumably occurred on members of 

 these groups collected by the 'Siboga' have escaped detection, as the "hosts" in question were 

 not submitted to me for examination. Discoveries of specimens of Loxosoma on members of 

 these groups have for the most part been due to the accidental inclusion of fragments of the 

 respective "hosts" in bottles labelled as Polyzoa. The systematic examination of the 'Siboga' 

 collection of Hydroids would almost certainly have resulted in a considerable addition to the 

 list of specimens and species recorded; while it may further be pointed out that the material 

 submitted for examination included hardly any Algae. 



The collection worked out was received in 583 bottles and tubes, which were numbered 

 consecutively from 1 to 583 in the order in which they happen to have been received. Although 

 these numbers were given, in the first instance, for convenience of reference during the progress 

 of the work, I have considered it important to record them in the subjoined systematic account 

 of the collection. It will thus be possible to yerify or correct my statements by reference to 

 the actual specimens on which they are respectively based. I think it well to emphasize this 

 point because, in some accounts which have been published — for instance in Busk's 'Challenger' 

 Reports — it is sometimes difficult to know what specimens are referreel to, in the case of an 

 account based on specimens from several distinct localities, and perhaps not rightly referred to 

 the same species. 



The specimens here recorded thus bear arbitrary numbers, from 1 to 583; and in each 



case the species found in a single bottle are further distinguished by letters (A, B, C ), 



given to them in the order in which they were sorted out. Every specimen in the collection 

 thus bears a distinctive symbol of its own. I propose to give a list of the specimens examined, 

 arranged under Stations, at the end of the Report. 



In view of the fact that no general account of the Oriental species has hitherto been 

 published, and of the convenience of having the description of the Polyzoon-fauna of so important 

 a district recorded in one place, I have ventured to prepare figures of nearly all the species, 

 even though many of them are already well knovvn. This course appears to me the more 

 defensible because the publication of figures will enable other workers to criticise more effectively 

 the correctness of my determinations. In many works which have been published — and on 

 which, it may be, conclusions relating to Geographical Distribution have been based — the 



