140 



GEODTA AGASSIZII. 



maximum averages (per cent) in a commensurate manner, the number, different 

 in each case, with which the general maximum average nmst be multipHed to 

 make the product 100 mm. was ascertained by dividing 100 mm. by the general 

 maximum average of the dimension in question (II). With these numbers, 

 which are given in III, the deviation of each dimension from the means (V) was 

 then multiplied. The product thus obtained is the percentage (commensurate) 

 deviation given in Vl. 



To bring out more clearly the significance of the commensurate numbers 

 given in VI, I have represented the variations of the spicule-dimensions ex- 



