356 PROCEEDINGS^ OF THE NATIONAL MUSEUM. vol.47. 



VARIATION IN PREOCULARS. 



The normal condition is a single preocular. Where two exist it 

 is due to the fragmentation of the lower one-third of the normal 

 shield. In many normal specimens the lower one-third of the shield 

 is indented at the margins and is lighter in color. 



Per cent. 



1 normal 86 



1-2 asymmetrical 10 



2 bilateral 4 



VARIATION IN POSTOCULARS. 



The normal condition is three shields. Where two exist it is due 

 to the fusing of the normal middle and lower shields and where 

 there are four it is due to the normal lower shield being horizontally 

 divided. In some normal specimens the lower shield is enlarged and 

 shows traces of a tendency to become divided. 



Per CMit. 



3 normal 80 



3-2 asymmetrical 10 



3-4 asymmetrical 6 



2 bilateral 2 



4 bilateral 2 



VARIATION IN ANTERIOR TEMPORALS. 



Per cent. 



1 normal 94 



1-2 asymmetrical 4 



2 bilateral 2 



VARIATION IN POSTERIOR TEMPORALS. 



Per cent. 



2 normal 82 



2-3 asymmetrical 12 



3 bilateral 6 



VARIATION IN SUPRALABIALS. 



The normal condition is to have 8 supralabials with the fourth 

 and fifth entering the eye. Where the number is reduced to 7 it is 

 due to the fusing of the normal second and third shields; in this 

 tyi^e the third and fourth enter the eye. Wliere the count is in- 

 creased to 9 it is due to the dividing of the normal eighth shield into 

 2 in which the posterior is the smaller. 



Per cent. 



8 normal 94 



8-7 asymmetrical 4 



8-9 asymmetrical 2 



VARIATION IN INFRALABIALS. 



The normal condition is to have 10 infralabials. Where the num- 

 ber is increased to 1 1 it is due to the normal fourth shield being 

 divided. Where it is decreased to 9 it is due to the normal third 

 and fourth shields (33 per cent), the normal seventh and eighth 



