186 



PROCEEDINGS OF THE ACADEMY OF 



[Mar., 



more dominant, the cross-bands of the back ahiiost disappear or 

 persist last in the cephalic half of the body, also occasionally near 

 the anus. In all (except two) of the large specimens the tail is 

 perfectly black on the venter, and this usually extends ahead of the 

 anus for 20-30 gastrosteges; in one large specimen (No. 6,214) the 

 same ventral area both ahead of the anus and on the underside of the 

 tail was merely heavily blotched with black. In the young speci- 

 mens the labials are heavily marked with rich brown which is more 

 or less obscure in adults. Usually the upper labials in the adults 

 are immaculate or with few dark spots, but the infralabials retain 

 more or less of the brownish markings of the young stage. The 

 postocular brown band bordered below by the yellowish labial line 

 and above by a pale streak is persistent in all. 



6210 



6210 



6129 



6127 



6215 



Fig. 14. — Ancistrodon piscivorus Lacep. 



Dimensions and Variations. — These specimens vary in length 

 from 38.3-96.7 cm., the tail 6.5-15.1 cm., or usually 6 times in the 

 total length, the range being 5|-6j times; the gastrosteges are 

 133-144, the average 141; the urosteges 45-52, the average 48; 

 anal entire; usually the first urostege is divided, then follows 25-30 

 entire individual urosteges, with the remaining caudal ones divided. 

 The strongly keeled scale rows range from 28-25-23 to 25-25-21, 

 in all the count being 25 around the middle of the body; usually the 

 supralabials are 8 in number, five of the sixteen specimens, however, 

 have variations. One has 7 on the right side and 9 on the left side, 

 two specimens 9 and 8 and two 8 and 7; the 3d and 6th supralabials 

 are largest; eye resting on the 3d, except in three instances where 

 9 supralabials occur. Then, the eye rests on the 4th, because the 

 extralabial comes in the normal second or third area. The approach 



