Nov. 5 

 1923 



AMARAL — NEW GENERA AND SPECIES OF SNAKES 93 



Sibij?iomorphus barbouri is related to S. articulatus (Cope), 

 S. incertus (Jan.), S. gracilis (Boulenger), 1 and S. bolivianus 

 (Werner). 2 It differs from S. articulatus in the color and mark- 

 ings of the head and in the number of the ventrals and the 

 subcaudals; from S. incertus in having no loreal, a semi-divided 

 nasal, and four pairs of chin shields; from S. gracilis in the 

 color and in the number of chin shields; and from S. bolivianus 

 in the color, the length of the internasals, the number of tem- 

 porals and chin shields, and in having no loreal. 



Sibynomorphus garbei sp. nov. 



Body slender, compressed laterally; head very distinct from neck; 

 pterygoid teeth present; eye large, with vertically elliptic pupil. 



Rostral broader than deep, scarcely visible from above; internasals 

 about half as long as the praefrontals; frontal pentagonal, a little longer 

 than broad, shorter than its distance from the end of the snout and than 

 the parietals, which are short and broad; nasal entire; loreal large, square; 

 no praeocular; 2 postoculars; temporals, 1 + 2/1 + 3; 9/8 upper labials, 

 4th, 5th and 6th (4th and 5th) entering the orbit; 1st lower labial in con- 

 tact with its fellow behind the symphysial; 3 pairs of chin shields (on the 

 right side the two posterior fused), anterior a little longer than broad. 



Scales in 15 rows, vertebral moderately enlarged; ventrals, 192 + 1/2; 

 anal entire; subcaudals, 112 pairs. 



Yellowish white above, with a dorsal series of round brown spots extend- 

 ing down to the sides of the ventrals, sometimes fused on the vertebral line 

 with those of the opposite side; every interspace of the spots usually oc- 

 cupied by one darker blotch, which changes into a short transverse line 

 along the middle of the body; head whitish, with four dark brown dots dis- 

 posed as a cross on the fronto-parietal suture, the parietals and the parieto- 

 occipital suture; belly whitish, speckled and laterally lineolated with 

 brown. 



Total length, 555 mm.; tail, 165 mm. 



1 G. A. Boulenger, Descript. of new Batr. and Rept. from Northwestern Ecuador, 

 Ann. Mag. Nat. Hist., (7), DC, 1902, p. 47. 



2 F. Werner, Ueber neue o. seltene Rept. d. Naturhistorischen Museums in Hamburg, 

 1909, pp. 240-241, in Zool. Jahrbiichern, XXVIII, 1909, p. 282; Synop. der Schlangen- 

 familien der Amblycephaliden and Viperiden, 1921, p. 198. 



