118 University of California Publications in Zoology [Vol. 11 



NuMBr;R OF Seizing Jaws. — These structures we found to vary 



from 6 to 10, the usual number being 8 or 9. Text figure 3 shows 



50- 



40- 



30 



20- 



10- 



6 7 



Fi-;. 3 



8 9 10 



in addition that out of 19S rows of jaws about 1 per cent had 6 

 jaws, while 13 per cent had 7. 4(i per cent 8, 39 per cent 9, and 

 1 per cent 10. 



However table 10, as well as its correlation coefficient 

 (r = 0.457 ± 0.0372) shows that, while the length of animal and 

 number of jaws are positively associated, the correlation is not 

 so pronounced as in the case of anterior and posterior teeth. 

 Still an examination of the numbers in brackets reveals the 

 following facts: 



