ON FOSSIL POLTZOA. 97 



docs it stand in regard to the level of the water in the neighbouring streams, or sea ? 



8. Analysis of the water, if any. Does the water possess any marked jjeculiaritu 1 



9. Section, with nature of the rock passed through, including cover of Drift, if any, 

 with thickness ? 9a. In which of the above rocks were springs of water intercepted ? 



10. Does the cover of Drift over the rock contain surface springs 1 11. If so, are 

 these land springs kept entirely out of the well ? 12. Are anv large faults known 

 to exist close to the well 1 13. Were any brine springs passed through in making 

 the well ? 14. Are there any salt springs in the neighbourhood ? 15. Have any 

 wells or borings been discontinued in your neighbourhood in consequence of the 

 water being more or less brackish? If so, please give section in reply 10 query No. 9. 

 16. Kindly give any further information you can. 



Fifth and last Report of the Committee, consisting of Dr. H. C. 

 Sorby, F.R.S., and Mr. G. E. Vine, appointed for the purpose of 

 reporting on Fossil Polyzoa. Draivn up by Mr. Vine. 



The classification which has been adopted in this Report is that 

 formulated by the Rev. Thomas Hincks for his work on British Marine 

 Polyzoa, which seems to be in the main accepted by Mr. A. W. Waters 

 for his various papers siuce the publication of Hincks's work. 



The classification of D'Orbigny > was based upon certain characters 

 which, as Mr. Hincks says, had one good feature at least : his family 

 groups had a wide range, and embraced many diversities in the mode of 

 growth. ' His genera, on the other hand, are often founded on utterly 

 trivial features, and have been multiplied indefinitely to represent every 

 insignificant variation of habit.' Mr. Waters, in his paper on the 

 'Bryozoa from the Pliocene of Bruccoli,' says that the classification was 

 based upon many characters by D'Orbigny, without his ' understanding 

 their zoological signification, and the consequence was that some form's' 

 could actually belong to several genera .... D'Orbigny attached much, 

 greater importance to the form of the cell than to the mode of aggregate 

 growth, and in some cases signified the form of a colony by an° affix, so 

 that there was Eschara and liept-esclmra, the first erect and the second 

 mcrustmg.' His knowledge, however, ' of Poljzoan form is perhaps 

 unsurpassed, and by his clear diagnosis and splendid plates he has given 

 us a new revelation of the structural variety and beauty of the class/ 2 



« We owe to Professor Srnitt the first serious attempt to substitute a 

 natural system for the purely artificial arrangement hitherto in use 

 He has aimed at a genealogical classification, starting with the proposition 

 that the variations of species follow the line of their development and 

 may be in a great measure explained by it.' In dealing, however with 

 this question Mr. Hincks points out how difficult to the mere systematist 

 the attempt to classify upon genealogical principles would be—' if it 

 should ever be feasible '—and if this would be difficult in dealino- with 

 living, the difficulties would be innumerable in dealing with fossil species 

 in spite of this, then, there is another important feature in Professor 



bmitts system that is far more practicable 'the place 



which he assigns to the Zooecium in the construction of families and 

 genera. The mere mode of growth he treats as a perfectly subordinate 

 character, and bases his divisions chiefly on the essential element of the 

 structure of the cell. In practice, this principle applies chiefly to the 



i oo f al Fmnq - Ter - CrH - TOL v - ' Hincks, op. cit. p. cxx. 



a. 



