152 



COLUBIUD.f:. 



frontal once and one third to once and a half as long as broad, 

 nearly as long as or shorter than its distance from the end of the 

 snout, as long as or longer than the parietals ; an azygous shield 

 separates the prcefrontals ; eye usually encircled by three to five 

 shields, in addition to the supraocular ; temporals 1 + 2 ; seven 

 upper labials, third or fourth rarely entering the eye ; four or five 

 lower labials in contact with the anterior chin-shields ; posterior 

 chin-shields small. Scales in 21 rows. Ventrals 131-147; anal 

 divided ; subcaudals 29-44. Yellowish or pale brown above, with 

 throe series of large black or brown black-edged spots ; three black 

 A-shaped bands on the head and a larger one on the nape ; lower 

 parts black and yellow (red ?), the two colours in nearly equal 

 proportion. 



Total length 560 millim. ; tail 80. 



Southern Brazil, Paraguay, Uruguay, Argentina, Southern 

 Chili. 



a-c. 3 (V. 136 ; C. 40), 

 $ (V. 131 ; C. 29), & 

 yg. (V. 145 ; C. 40). 



d. c? (V. 134; C. 41). 



e-ff. <$ (V. 143 ; C. 44) 



& yg. (V. 136, 145 ; C. 



35, 40). 

 h-i. d (V. 141; C. 43) 



& $ (V. 132 ; C. 33). 

 k. $ (V. 136 ; C. 33). 

 /. $ (V. 138; C. 36). 

 m-n. d (V. 147 ; C. 39) 



& $ (V. 135; C. 36). 

 o. $ (V. 133 ; C. 34). 



p. Skull. 



Rio Grande do Sul. Dr. H. v. Ihering [C.]. 



San Lorenzo, Rio Dr. H. v. Ihering [C.]. 



Grande do Sul. 

 Dept. of Soriano, R. Havers, Esq. [P.]. 



Uruguay. 



Montevideo 



Buenos Ayres. 

 Buenos Ayres. 

 Argentina. 



S. Chili. 

 Argentina. 



G. Wilkes, Esq. [P.]. 

 Mr. Wilson [C.]. 



A. Lane, Esq. [C.] ; 

 H. B.James, Esq. [P.]. 



2. Lystrophis histricus. 



Heterodon histricus, Jan, Arch. Zool. Anat. Phys. ii. 1863, p. 224, 

 and Icon. Gen. 11, pi. iv. fig. 2 (1866) ; Steindachn. Verh. zool.- 

 bot. Geg. Wien, 1864, p. 232, pi. vi. 



nattereri, Steindachn. Novara, Kept. p. 90 (1867). 



Frontal as long as broad, shorter than its distance from the end 

 of the snout, as long as the parietals ; no azygous shield separating 

 the prsefrontals ; one (or two) pra>- and two (or one) postoculars ; 

 temporals 1 + 2; seven upper labials, third and fourth entering the 

 eye ; five lower labials in contact with the anterior chin-shields ; 

 posterior chin-shields small. Scales in 19 rows. Ventrals 133-144 ; 

 anal divided ; subcaudals 27-37. Reddish above, with more or less 

 regular black cross bars edged with yellowish; sides yellowish, 

 spotted with black ; three black A-shaped bands on the head, and a 

 larger one on the nape ; yellowish-white inferiorly, spotted with 

 black. 



