1915.] NATURAL SCIENCES OF PHILADELPHIA. 35 



Regarding the relative length of body and tail, we would expect 

 the proportion to run rather low since the brood comes from Tampa 

 Bay. But this is not the case. The range is 2o.5%-27.8%, average 

 27.1%. 



From this it may be seen that but one race of Natrix compressi- 

 cauda can be recognized. 



