HERPETOLOGY OF PORTO RICO. 



705 



m 



v 



m 



m 



equaling its distance from the tip of the snout and the parietal suture; 

 nostril between two nasals; loreal moderate, trapezoid, the posterior 

 border being strongly convex; one preocular separated from frontal; 

 two postoculars, the lower one very narrow; temporals 1+2; 8 supra- 

 labials, third, fourth, and fifth entering eye, the fifth and following 

 ones abruptly much higher than the anterior ones; 5 lower labials 

 in contact with anterior chin-shield, which is much shorter than the 

 posterior: 19 rows of smooth scales with two conspicuous apical 

 pores; 183 ventrals; anal double; 118 pairs of subcaudals. Color (in 

 alcohol) above brownish drab, the individual scales irregularly tipped 

 and edged with dusky; underneath whitish with dark-drab mottlings 

 on chin and throat and a series of similarly colored dots on the lateral 

 canthus of each ventral shield, 

 forming a dotted line on each 

 side of the abdomen, each ven- 

 tral, moreover, posteriorly more 

 or less irregularly edged with 

 brownish drab; a few brownish 

 irregular spots on the labials and 

 upper head shields, with a double 

 series of elongate brownish spots 

 on the upper neck; from anterior 

 nasal through eve a dark-brown- 

 ish streak continuing on the sides 

 of neck and body as a broken line 

 of elongate spots; these spots which on the sides of the body occupy 

 the lower half of every second or third scale in the fifth scale row, the 

 upper half being whitish or decidedly paler than the ground color. 



Dimensions. 



mm. 



Tip of snout ti i tip of tail 1, 130 



Vent to tip of tail 340 



Variation. — As in the foregoing species, the scale formula and other 

 characters derived from the scutellation are unusually constant. Men- 

 tion has alread} r been made of No. 25556, from Culebra Island, the 

 only one out of 34 specimens to have the exceptional number of 17 

 scale rows. At the same time it was remarked that this specimen is 

 easily identified as Ahqphis anUllensis by the characteristic pattern of 

 the fifth scale row — a feature first mentioned by Mr. Meerwarth. This 

 marking appears to be constant, however variable the coloration may 

 otherwise be. On the whole the coloration is much as in the speci- 

 men described above, but in the smaller specimens there is sometimes 

 an indistinct dusky vertebral line from the parietal suture backward, 

 while on the posterior part of the body and on the tail the scale rows 

 next to the ventrals darkens so as to form a more or less distinct longi- 

 tudinal band. 



NAT mus 1902 45 



Fig. 174.— Alsophis antillensis. Color pattern 

 around middle of body. No. 25557, U.S.N.M. 



