336 REPORT OF NATIONAL MUSEUM, 1898 



CC. Two cauthal scales. 



rj. No black neck collar. 



6. Two or more parifttals. 



Two rows of large supraoculars ; scales large, sub- 

 equal; green, a black shoulder patch. 



^Sf. taenioenemis Cope. 



One row of large sTipraoculars ; scales large, sul>- 



e(inal, eight in a bead length; abdominals and 



inferior tibials smooth ; green, a black shoulder 



patch S. viviparns Cope. 



One row of large supraoculars ; scales subequal, 

 smaller; eleven in a head length; abdominals 

 and inferior tibials keeled; brown, with lateral 



stripes S. tliayern Baird and Girard. 



G0. One parietal (sometimes postparietals). 



Scales of sides of neck and shoulder smaller; 20 

 femoral pores; two rows of dorsal spots. 



S. hiseriatus Hallowell. 

 Scales of side of neck and shoulder smaller; 44 

 dorsal rows of scales, 9-10 in a head length; fem- 

 oral pores 12-17; males crossbarred, females 

 banded; head plates sometimes wrinkled. 



S. undiilatus Latreillc, 

 Like undulatus, but larger; scales larger, dorsals 

 in thirty-three rows; femoral pores ten; brown 

 spotted above, throat not blue. 



S. spinosus Wiegmann. 

 7/77. A black neck collar. 



"One large toav of supraoculars; dorsal scales 

 strongly mucronate; throat and sides of belly 

 blue; collar complete, not light bordered." 



S. acantliinus Bocourt. 



One or two rows of large supraoculars ; dorsals not 



or but little mucronate; collar complete, light 



bordered ; sides of belly blue, throat greenish or 



spotted S. iorqiiatus Greene and Peale. 



AAAA. Both dorsal and lateral scale rows converging posteriorly. 



Forty-three scales between occiput and groin ; two 

 cauthal scales; two rows larger supraoculars; 

 collar a narrow black line directed backward 

 from each shoulder, pale bordered behind, mostly 

 interrupted ; throat not blue . . (S'. dugenii Bocourt. 

 One canthal scale; very few scales between large 

 supraoculars and superciliaries ; two small pari- 

 • etals ; two rows of blue spots on belly. 



S. pyrrhocephalus^ Cope. 

 II. Supraoculars separated from supraorbitals by a row of scales; from superciliaries 

 by laiiciforiu scales like superciliaries. 



A. Dorsal rows parallel, laterals large, oblique. 



B. One parietal and two canthal scales. 



A black collar; seven scales in a head length; 

 head scales smooth ; back not cross-banded. 



S. serrlfer Cope. 



No black collar; twelve scales in a head length; 

 head scales smooth ; inferior tibial and postanal 

 scales smooth ; cross-banded . . S. tristichus Cope. 



' Many specimens of this species enter Division II. 



