16 



todes in "The American Naturalist" for 1894, p. C14. Addi- 

 tional material enables me to extend this as follows : 



I. Scales in Fifteen Rows. 



Frontal twice as long as wide; temporals 1-2-3; labials eight; 

 vertebrate enlarged, truncate ; genials equal ; spotted 

 above, below speckled B. lentiferus Cope. 



II. Scales in Seventeen Eows. 



a Frontal plate twice as long as wide; eight upper labials; genials 

 subequal; spots above indistinct; below speckled, with 

 medium stripe H. inornatus Blgr. 



aa Frontal plate not twice as long as wide ; lateral bor- 

 der exceeding anterior. 

 /3 Vertebrals enlarged and truncate. 



Pregenials twice as long as postgenials, joining only four labials; 

 seventh superior labial longer than high; temporals 2-3; 

 scales of eighth row equal to those of first; belly speckled. 



H. hemigenius* Cope. 



Pregenials equal postgenials, joining five labials; eighth and first 

 row of scales equal; seventh superior labial higher than long; 

 dorsal spots approximate; temporals 2-3; belly with three 

 series of spots H. stratissimus Cope. 



Pregenials equal postgenials, joining usually five labials; eighth 

 row smaller than first, seventh superior labial higher than 

 long; temporals 1 or 2-2; below speckled H. cenchoa Linn. 



Pregenials equal or shorter than postgenials, as in JET. cenchoa, 

 but temporals 2-3 ; ground color very pale ; spots black, reach- 

 ing belly ; yellow bordered ; belly speckled . . . . S. leucomelas Cope. 



. /3/3 Vertebral scales not enlarged, or if a little enlarged, 

 not truncate. 



*HlMANTODES HEMIGENIUS Cope. 



Scales in seventeen rows, those of the vertebral row wider than long, 

 truncate; those of the eighth row equal those of the first. Head oval, 

 muzzle short, equal diameter of eye. Frontal plate two-thirds as wide 

 as long, anterior suture shorter than supraocular. Common suture 

 of parietals a little shorter than frontal plate. Superior labials eight, 

 fourth and fifth bounding orbit, seventh like eighth, longer than high. 

 Loral higher than long; oculars 1-2 (upper end of preocular on one side 

 cut off); temporals 2-3. Postgenials half as long as pregenials; the 

 latter in contact with only four inferior labials. Gastrosteges, 246; 

 urosteges, 146. 



