72 PROCEEDINGS OF THE ACADEMY OF 



postoculavs two, small, ^ye small. Temporals 1-2 narrow. 

 Superior labials seven ; eye over the third and fourth, fiftli and 

 sixth the longest ; geneials rather short, subequal. Scales in seven- 

 teen longitudinal series, rather wide ; the first not materially 

 larger. Gastrosteges 137 ; anal 1 ; urosteges 32. Total length, 

 m. .305 (12.5 inches) ; of head .011 ; of tail .046. 



Color light brown, with black triangular spots on each side of 

 the middle line, the apices directed downward and extending lialf 

 way to the gastrosteges. The intervals between the apices are 

 about four scales in length, and are centrally darker tlian imme- 

 diately round the black spots. The spots are sometimes con- 

 nected b}' a black vitta on the median line, giving, when they 

 alternate, the appearance of zigzag band. Top of head dark 

 brown ; lower surfaces and lips pale and unspotted. 



The neural osseous plate is deeply longitudinally fissured, each 

 half having a tubercularly rugose superior face. The anterior 

 border is notched, while the posterior is a little produced on each 

 side of the groove. Length of plate, m. .0018 ; width of plate, 

 .0013. 



From Nauta on the Peruvian Amazon ; two specimens obtained 

 by Professor James Ortou during his last survey of that region. 



