566 



VIPERIB*. 



rostralis raised, forming a serration ; three series of scales between 

 the e5'e and the labials ; loreal pit separated from the labials by 

 small scales ; temporal scales keeled; 11 upper labials. Scales in 

 21 rows, dorsals strongly or very strongly keeled. Ventrals 149- 

 171 ; anal entire ; subcaudals 41-49 pairs. Tail prehensile. Olive 

 or brown above, sometimes speckled with black, with a dorsal series 

 of large rhomboidal dark spots or an undulous or zigzag band ; a 

 light, dark-edged streak from the eye to above the angle of the 

 mouth ; belly yellowish or brownish, speckled or powdered with 

 blackish ; a more or less distinct series of light spots along each 

 side close to the ventrals. 



Total length 570 millim. ; tail 75. 



Mexico. 



a. Yg. (V. 149; 0. 42). Orizaba. 



b-c. 5 (V. 166; C. 45) Omilteme, Guerrero. Mr. H. H. Smith [0.1 ; 

 & yg. (V. 163 ; 0. 49). F. D. Godman.Tilsq. 



[P.]. 

 rf. d (V. 150; 0.41). Oaxaca. M. Sall6 [0.]. 



36. Lachesis lateralis. 



Bothriechis lateralis, Peters, Mm. Berl. Ac. 1852, p. 674. 

 Bothrops lateralis, F. Mull. Verh. Nat. Ges. Basel, vi. 1878, p. 401. 



Snout rounded, with moderately marked canthus. Eostral much 

 broader than deep ; nasal divided ; upper head-scales moderate, 

 imbricate, keeled, largest on the snout and vertex, 7 across between 

 the supraoculars, which are narrow; internasals small, with 

 smaller scales between them ; two series of scales between the eye 

 and the labials ; temporal scales keeled ; 9 upper labials, second 

 forming the anterior border of the loreal pit, fourth and fifth 

 largest. Scales rather strongly keeled, in 21 or 23 rows. Ventrals 

 171 ; anal entire ; subcaudals 59, single. Tail prehensile. Green 

 above and below, with a yellow line running along the outer row 

 of scales ; back with some black-and-yellow short cross-bars. 



Total length 485 millim. ; tail 75. 



Costa Rica. 



a. Hgr. (Sc. 23 ; V. 171 ; Costa Rica. O. Salvin, Esq. [0.1. 



0. 59). 



37. Lachesis hicolor. 



Bothrops bicolor, Bocourt, Ann. 8c. Nat. (5) x. 1868, p. 201; 



F. Mull. Verh. Nat. Ges. Basel, vii. 1882, p. 156. 

 (Bothriechis) bemouillii, F. MOM. Verh. Nat. Ges. Basel, vi. 



1878, p. 399, pi. iii. fig. A. 

 Bothriechis bicolor, Giinth. Biol. C.-Am., Rept. p. 189 (1896). 



Closely allied to L. lateralis, but upper head-scales smaller (10 

 or 11 longitudinal series between the supraoculars), and 10 or 11 

 iipper labials not very unequal in size, the second not entering the 

 loreal pit. Scales in 21 rows. Ventrals 164-167; subcaudals 

 62-67, single. Uniform green above, yellowish beneath. 



