1911.] NATURAL SCIENCES OF PHILADELPHIA. 221 



is in every way established. They show the following variations in 

 some of the principal characters. 



Head 3| to 4f ; depth 3| to If-; D. usually 18, often 17, rarely 16 

 or 19; A. usually 29, often 28, seldom 27; scales in 1. 1. usually 32, 

 seldom 30, 31, 33 or 34 + usually 4, often 3; usually 4 scales above 

 1. 1., sometimes 5; usually 5 scales below 1. 1., frequently 4, rarely 6; 

 predorsal scales usually 23 or 24, sometimes 21, 25 or 26; snout 4% 

 to 5 in head, measured from snout tip to hind bony opercle edge; 

 eye 5i to Q^; maxillary If- to If; interorbital 3| to 3|; length 11^ to 

 234 inches. 



