i9o: 



NATURAL SCIK.WKS OF I'lll LA1)I;LI'II1 A. 



233 



In the following tables the figures stand for the whorl, while the 

 letters are used for the different ontogenetic stages as follows: 



A — Smooth stage. D— Spiny stage. 



B — Curved rib stage. E — Senile stage. 



! C — Cancellated stage. I — Individual variation. 



1 5 6 7 s 9 10 11 12 



Mount Lebanon, La. 



Lewis House, two miles 

 east of Alto, Tex. 



Nine miles southeast of 

 Jewett, Tex. 



Smithville, Tex. 



Hurricane Bavou, Hou>- 

 tonCo.,Tex. 



Alabama Bluff, Trinity 

 River, Houston Co., 

 Tex. 



Shipp's Ford, Bastrop 

 Co., Tex. 



Moseley Ferry, Tex. 



Moseley Ferry (Jackson 

 Strain). 



St. Maurice, La. 



A 



A 



A 



A 



A 



A 



A 



A 



A 



g- 



B 



li 



II 



B 



B 



B 



-H- 



^ 



B 



B 



-H- 



D 



D 



II 



D 



D 



D 



D 



D 



a 



D 



Table I. — Showing variability in the Icnjith of tlie smooth stage and relative 

 constancy in the beginning of the spiny stage in the Loavcf Claiborne races 

 of .1 . pdrosa . 



