BRYOZOA FROM ZANZIBAR. 



461 



earlier authors in a sense different from tliat applied to them 

 for generations ; and not only that, hut genei'ic names now well 

 established are shifted to be used instead of other well-established 

 names. Cellaria is to be replaced by Cellularia, a name that has 

 been used in numerous senses during the lifetime of most of us. 

 There is no rule obliging us to revert to old names which were 

 made for genera without any adequate and recognisable descrip- 

 tion ; but even if a rule were being broken, we should continue 

 to do so in order to stay the appalling confusion caused by this 

 desire to keep alive a name in its doubtfully supposed original 

 sense. Cellaria still means for me what it has meant all my 

 scientific life. I do not accept Lepralia as meaning Memhrani- 

 jyorella, and this Levinsen also refuses to do and gives an amended 

 description of Membraniporella ; but I am not prepared to accept 

 Aspidelectra, and should place melontha under Alemhranijjorella. 

 Nor is the variously used Escharoides a satisfactoiy name, seeing 

 that it was only given for a subgenus of Cellepora based upon 

 characters seen to be useless. Discopora is another genus that 

 should have been dropped, as it was quite insufficiently described 

 at first ; in fact, the name was given by Lamarck to a Cheilostome 

 and by Fleming to a Oyclostome, so that it has been employed for 

 all kinds of unrelated things, as Cellepjova, Haloporella^ Membrani- 

 p)ora^ Mucronella, Smittitia, Palmicellaria, Diastopora, Lichenopora^ 

 Tu}nd\p)ora^ etc., and has been variously used by palaeontologists. 

 It has not been proposed to retain Discopora on account of the 

 definition, which now tells us nothing, but from what is supposed 

 to be the first-mentioned species of an incongruous group. 



Such changes back to discarded genera add much to the diffi- 

 culties of those who are closely following all that is written ; and 

 are not these premature and puzzling changes of names keeping 

 back new workers from entering the thinning ranks ? Until we 

 are sure of the characters, and have enough material to test the 

 relationships, "vve must often gather information round species 

 and genera the names of which we know will ultimately be 

 changed or disappear. 



1 have again to thank Mr. Kirkpatrick for allowing me to 

 make frequent comparison with the British Museum col- 

 lections. The Plates were mostly drawn before the appearance 

 of Levinsen's work, otherwise they w^ould have been slightly 

 differently arranged. Miss Thorn ely's paper, " The Marine 

 Polyzoa of the Indian Ocean from H.M.S. Sealark," Trans. 

 Linn. Soc. vol. xv. pp. 137-157, has also appeared during the 

 preparation of my paper. It materially increases our knowledge 

 of the distribution of tropical Bryozoa from moderate depths. 



Other groups collected by Mr. Crossland from Zanzibar have 

 already been described by specialists in the Proceedings of this 

 Society. 



