398 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 93 



110461) ; Cajon de Piedra (No. 110422) ; Tehuantepec (Nos. 110423- 

 4) ; and Rio Grande, 12 miles north of Niltepec (No. 110425). 



Scale rows 23-23-19, except in one with 25-25-21 rows; ventrals 

 143 to 153 in five males, 147 to 155 in six females ; caudals 36 to 42 

 in five males, 32 to 37 in six females; supralabials 9-9 in one, 9-10 

 in four, 10-10 in four, 10-11 in two; infralabials 10-10 in three, 10-11 

 in two, 11-11 in four, 11-12 in one, 12-12 in one; preoculars 3-3 ex- 

 cept in one which has 4-4; suboculars 1-1 except in one which has 

 2-2 ; postoculars 2-2 to 3-4 ; bands on body 14 to 19. 



The Museum has six others, 8 one from Puerto Angel (No. 46422), 

 five from Tehuantepec, Oaxaca (Nos. 30266-70) . 



BOTHROPS MELANURUS (Muller) 

 Tritneresurus garciai Smith, Proc. Biol. Soc. Washington, vol. 53, pp. 55-64, 1940. 



One specimen, a paratype of garciai (No. 108602), is from Caca- 

 loapam, Puebla. 



The Museum has no others of the species. 



BOTHROPS MEXICANTJS (Dumeril and Bibron) 



Five specimens are in the collection, four (Nos. 110426-8, HMS. 

 No. 7654) from Piedras Negras, Guatemala, and one (No. 110429) 

 from Santa Rosa, near Comitan, Chiapas. 



The Museum has no others of the species from Mexico. 



The most conspicuous difference between mexicanus and nummifet 

 in pattern is the shape and lateral extent of the dorsal blotches. In 

 the former the blotches are large, dark brown rhombs that extend 

 laterally to the tenth or as far as the sixth scale row. Sometimes 

 these rhombs are black-edged. Opposite the lateral corner on each 

 side is a short, black or dark brown transverse bar, sometimes reach- 

 ing nearly to the ventrals. Usually, except on the anterior third of 

 the body, the lateral bars are fused with the dorsal spots. Fre- 

 quently, over all or a part of the body, the dorsal blotches are fused 

 in pairs, producing a broad cross band ; the lateral spots remain dis- 

 tinct from one another. The bands or rhombs may be somewhat 

 staggered by displacement on the midline. In nummifer the pat- 

 tern is of much the same character, except that the dorsal blotches 

 tend to be less angular and more rounded, all are black-edged, and 

 do not fuse with the lateral spots. The median blotches may be stag- 

 gered and so fused with one another as to produce a rather broad, 

 zigzag median band (such a variation does not occur in mexicanus), 

 but they do not fuse in pairs as they frequently do in mexicanus. 



8 Ainaral, 1929b, p. 22. 



