158 PROCEEDINGS OF THE ACADEMY OF [Feb., 



form, .535 as against .525. Comparing with these the other members 

 of this series we see that the dimensions continue to decrease on the 

 whole and the indices to increase, at least as far as Garrett's woods, 

 which is really beyond Mandeville; though the Ridge near Lincoln 

 forms (R. nr. L.) average somewhat higher than those of Garrett's 

 woods (G. W.) and Bloomfield (Blm.), they are also higher than the 

 wider form at Somerset Road colony (Sm. R.). The index of the 

 Ridge near Lincoln form is then somewhat higher than that of the 

 Garrett's woods form, but not higher than that of the Bloomfield form. 

 There is hence a slight irregularity in the curve of heights and indices. 

 The topography of the country renders it very probable that Garrett's 

 woods and Bloomfield are in a migration line from the north, in which 

 the Somerset and Somerset Road colonies would be the first stations 

 represented on this diagram, or in this collection; the Ridge near 

 Lincoln colony would probably be a station on another line from the 

 Somerset region. That the forms migrated from the north, the high 

 backbone of the island, after the last submergence of the island, is 

 almost certain from the topography; therefore the forms whose 

 measurements are given on this diagram, being arranged geographi- 

 cally, might represent the variation in a stock along a migration line. 



The Kendal Road — King Edward Hotel Woods Group. 



A similar migration line is probably represented in the lower part 

 of fig. 6, which gives the measurements for the Kendal Road (K. R.), 

 Benmore woods (Ben.), Cedar Hill woods (C. H.) and King Edward 

 Hotel woods (K. E.). In this series, again, variation begins with the 

 third whorl, and becomes more pronounced in the succeeding whorls. 

 The height and width decrease for the first three stations, but rise 

 again at the fourth. This series was arranged geographically, but 

 also to show a constant rise of index, as the Cedar Hill woods and 

 King Edward Hotel woods are about equally distant from the Kendal 

 Road Station. The rise in the index from the Kendal Road to King 

 Edward woods is, as the diagram shows, from .55 to .585; although 

 both width and height diminish from the one station to the other, the 

 index rises, that is, the spire rises proportionately to the width. 

 The index, therefore, gives a direct means of comparison of the relative 

 heights of the spires ; as it rises, the spire becomes higher. As has been 

 stated above, this change in form is observed in passing from station 

 to station in each of the series represented in fig. 6; that is, a geo- 

 graphical arrangement of the forms is also a morphological one. 



