SYNOPSES AND DESCRIPTIONS. 33 
HeEnicoprs. 
Wagler, 1830. 
Form stout, tapering to head and tail; head larger than the neck, 
broad behind, narrow forward, crown flat; tail tapering. Eyes mod- 
erate to small, pupil round. Teeth smooth, post maxillary larger and often 
isolated. Head-shields eight or nine. Internasals narrow in front or 
fused, generally in contact with the rostral. Nasal entire and grooved, 
or divided. With or without a loreal. Commonly 1—2 ante, and 2—3 
postorbitals, suborbitals rarely present. Scales keeled in 19—25 rows. 
Anal bifid. Subcaudals in two rows. 
Nasal divided ; 
internasals 2; scales keeled, in 19—21 rows 
variabilis. 
Nasal entire, grooved ; 
internasal 1; scales in 19 rows, keels few allenii. 
HELICOPS VARIABILIS. 
TRETANORITINUS VARIABILIS Dum. & Bibr., 1854, Erp. Gin. VII, 349. 
Fusiform; head distinct, narrow across the nasals, broad behind, de- 
pressed, crown flat; tail moderate, tapering rapidly near the base. Eye 
small, pupil round. Jaws nearly equal in length. Posterior maxillary 
teeth little larger, slightly compressed. Rostral broader than high, con- 
vex. Head-shields nine. Internasals small, irregular, subtriangular, not 
at all or but little in contact with the rostral. Prefrontals broader in front, 
longer than broad. Frontal pentagonal, truncate and narrower in front. 
Nasal in two parts, the small nostril between, nearer the upper margin. 
Loreals 2 (1—2), anterior smaller. Anteorbitals 2 (2—3), lower larger. 
Postorbitals 2. Temporals 1+2+3. Labials 8 
last largest, a single one (fourth or fifth) under the eye. Infralabials 
9, the two preceding the 
10—11, sixth largest (fifth or sixth). Submentals two pairs, posterior 
larger. Scales keeled, lozenge-shaped, truncate, in 21 rows (19—21), dor- 
sal finely striate, outer broader, nearly or quite smooth. Ventrals broad 
142 (137—158). Anal bifid. Subcaudals 65 pairs (65—78). 
Light greyish to dark brown, edges of scales lighter; young with irreg- 
ular indistinct blotches of darker. A light line on the outer two rows of 
scales from the neck to the tip of the tail, Belly yellowish white, mottled 
“ 
Mem,—vou, 1—3 
