Mr. G. A. Boulengcr on the Genus Pseudoxyrliopus. 313 



B. Scales in 21 rows ; frontal ft little longer 



than broftd ; two labials euteriug the eye. 



a. Rostral just visible from above; veutrals 



15o ; subcaudald 35 P. heterurus, Jan. 



b. Portion of rostral visible from above at 



least half a^ lou;:r as its distance from 

 the frontal; ventrals 142; subcaudals 

 4o-47 P. quinquelineatus, Gthr. 



C. Scales in 19 rows; ft-outal longer than 



broad ; portion of ro.'^tral visible from 

 above half as long as its distance from tho 

 frontal ; two labiiJs entering the eye ; 

 ventrals lo7-140; subcaudals 40-47 .... P. imerina, Gthr. 



D. Scales in 17 rows ; frontal a little longer 



than broad ; three labials entering the 



eye ; ventrals 1G2 ; subcaudals 42 P. punctatus, Ptrs. 



All agree in the following points : — Supraocular not more 

 than lialf the width of the frontal ; loreal longer than deep ; 

 one pra3- and two postoculars ; temporals 1 + 2 ; anal divided. 



List of the Species. 



1. Pseudoxyrhopus microps. 



Pseudoxyrhopns microps, Giiuther, Ann. & Mag. Nat. llist. (5) vii. 

 1881, p. 359, fig. 



Betsileo. 



2. Pseudoxyrhoims heterurus. 



Homahicephalus hcU-rurus, Jan, Arch. Zool. Anat. Phys. ii. 18G3, p. 280, 

 and Icon. Ophid. xvii. pi. iv. tig. 2 (18GG). 



Madagascar. 



3. Pseudoxyrhopus quinquelineatus. 



Liophis quinquelineatus, Giinther, Ann. & Mag. Nat. Hist. (5) vii. 1881, 

 p. 359, fig. 



Betsileo. 



4. Pseudoxyrhopus imerince. 



CoroneUa microps, Boulenger, Ann. & Mag. Nat. Hist. (6) i. 1888, 



p. 104, pi. V. fig. 4. 

 Liophis imerin<e, Giinther, Ann. & Mag. Nat. Hist. (G) v. 1890, p. 71. 



Imerina. 



L. imerince is the adult of the previously described G. 

 microps^ which name, however, is preoccupied by Pseudoxy- 

 rhopus microps^ Gthr. 



