■WB 



98 REPORT— 1884. 



Cheilostomata — but. the revolutionary step involves the breaking up of a 

 large proportion of the older genera and the wide dispersion of forms 

 hitherto most closely associated . . . . The variations of habit, which have 

 been made the criteria of genera, may occur within the limits of a species. 

 It is not the mode in which the cells combine, but the cell itself that is 

 the true test of relationship and the essential basis of a natural group.' ' 



With the Cyclostomata we have an increase of difficulties when dealing 

 with the cell alone, and it is almost impossible to suggest or carry out a 

 natural grouping of forms belonging to this sub-order. Yet even hero wo 

 have many special features in cell structure and cell arrangement that 

 may be advantageous to the systematist, and it is to be hoped that my 

 endeavoui's to keep certain groups intact may not bo wholly illusory. 



With regard to the second and third divisions of my Report, a few 

 ■words will, I think, suffice for the general student at least. At the 

 present time it is almost impossible to obtain a copy of the works, or 

 even lists of the species, alluded to or described by many very successful 

 labourers in my own special line of research, and, even if it were possible, 

 the descriptive text is as a matter of course found only in books published 

 in the mother tongue of the describers. Thus we have works on Fossil 

 Polyzoa published in the Swedish, Dutch, German, Italian, and French 

 languages, but very few, until quite recently, in the English. I now 

 reproduce, for the benefit of others, these almost inaccessible treasures, and 

 for the first time, I believe, have furnished to the pateontologist, if not 

 complete, very nearly complete lists of all known Polyzoan forms, from the 

 Upper Cretaceous epochs to the latest of the Glacial beds of Scotland. 



It may be well to address a few words to special workers on this 

 group. I shall be glad to exchange material from Silurian, Carboniferous, 

 Jurassic, and Miocene beds of North Italy, for material from any horizon, 

 not so much for the purpose of the mere possession of forms, but for the 

 higher purpose of making a critical examination of the whole of our 

 Fossil Polyzoa. In the exchanges — if any follow my request — I shall 

 regard of greater importance fewer forms if the strata whence obtained are 

 carefully noted. In the work on which I am engaged it will be evident 

 to all that specimens indifferently selected, or whose horizon is unknown, 

 are of but small value in a palajontological study lilco the present one.^ 



Sub-order I. Cheilostomata, Busk. 

 Familv I. Aeteids. 

 • ■ ■ Aetea, Lamouroux. 



Family II. EiicRATiiDii:. 



, . EuCRATEA, Lamouroux. Hdxleya, Dyster. 



Gemellaria, Savigny. Brettia, „ 

 SCRUPAKIA, Hincks. 



Family III. Cet.lularhd^. 

 Cellularia, Pallas. Scrupocellaria, Van Beceden. 



Menipea, Lamouroux. Cadebea, Lamouroux. 



Family IV. Bicellabiid/E. 

 BiCBLLARiA, Blainville. Beania, Johnston. 



BuGULA, Oken. 



' Hincks, ojf. rit. pp. cxxi. and cxxii. 



» Address, G. R. Vine, Attcrcliffc, Sheffield. 



