1915.] 



NATURAL SCIENCES OF PHILADELPHIA. 



155 



25 rows of Heterodon platyrhinus and simus. The temporals are 

 3^ on both sides in twenty-seven specimens, 3-4 on one side and 

 3-5 on the other in three specimens, and 3-4 and 4-5 in one specimen; 

 the supralabials are 8 in twenty-seven specimens, 9 in seven speci- 

 mens and 9-8 in three specimens; the infralabials are 11 in fifteen 

 specimens, 10 in three specimens, 12 in five, 13 in one, 10-11 in four, 

 10-12 in three, 11-12 in five and 12-13 in one. The orbital ring^ 

 exclusive of the supraocular is 10 cm both sides in thirteen specimens, 

 11 in one, 9-10 in two, 9-11 in two, 10-11 in fourteen, and 8-10 in 

 two, i.e., 22 of the 38 with number of oculars different on the two 

 sides. 



Rarely, the azygous plate may be cut off from contact with the 

 rostral by the prenasals (No. 6,186). One spotted specimen (No. 



HOrmoV 



6197 



6186 



6194 



6170 6204 



Fig. 6. — Heterodon platyrhinus Latr. 



6202 



6,197) has not the characteristic azygous plate at all. Unlike Dr. 

 Stejneger's Heterodon browni,^^ this specimen has the posterior projec- 

 tion of the rostral more than one-half of the suture between the inter- 

 nasals and their mutual suture, therefore less than that between the 

 prefrontals. Otherwise, it is very much like it. The specimen has 

 the following scutellation: gastrosteges, 123; urosteges, 55; anal 

 divided; scales 25-21-19; supralabials 8; infralabials 11; orbital 

 ring 10, not including the supraocular; temporals 3-5 on the right 

 side and 3-4 on the left side. These characters and a very similar 

 coloration bring it in almost perfect agreement with Dr. Stejneger's 

 H. hroivni from the other end of Florida, namely, Lemon City. A 

 black individual (No. 6,194) has the frontal transversely divided 

 into two plates. One specimen (No. 6,202) has 2 loreals on either 



3° Proc. Biol. Soc. Wash., XVI, pp. 123, 124. 



