MEASUREMENT OF ORGANISMS. 



8 9 10 



Sinuate, still stronger waves, height equals or exceeds 

 breadth (Fig. 19). 



Incised, with sharp, deep incisions (Fig. 20). 



15 



16 



17 18 19 



FIGS. 15-20. 



The quantitative expression of variation in these forms can 

 usually be easily obtained by using an index, or ratio of two 

 dimensions. 



greatest length 



Index of Lmearuess, r-r . 



greatest breadth 



greatest length 



" " Lauceolateness, r- -^- T , also angle aoc. 



greatest breadth 



greatest length area 



" " Oblongness, ^rrr, also -r-r . 



greatest breadth breadth 



(greatest Igth.) (greatest brdth.) 

 " " Ellipticity, - -> 



(greatest length) 



for values from 1 to .50. 



