78. LYSTEOPHIS. 151 



g. Yg. (V. 147 ; C. 41). Corumba, Mato S. Moore, Esq. [P.J. 



Grosso. 



h~i. cS (V. 137; C. 41) San Lorenzo, Rio Dr. H. v. Ihering [CI 



& 2 (V. 147; C. 38). Grande do Sul. 



k. Yg. (V. 157; 0.47). BrazU. 



^»n. Hgr. (S (V. 131; Asuncion, Para- Dr. J. Bohls TCI. 



C. 36) & 2 (V. 144 ; guay. 



C. 34). 



n. 2 (V. 146; C. 39). S. America. Zoological Society. 



o. Skull. Babia. 



p. Skull. S. America. 



78. LYSTEOPHIS, 



Heterodon, part., Dum. 8f Bibr. Erp. Gen. yii. p. 764 (1854) ; Giinth. 



Cat. Col. Sn. p. 82 (1858) ; Jan, Arch. Zool. Anat. Phys. ii. 1864, 



p. 218. 

 Lystrophis, Cope, Proc. Am. Philos. Sac. xxii. 1885, p. 193. 



Maxillary very short, shorter than ectopterygoid, with 4 or 5 

 small teeth, followed, after an interspace, by a pair of strongly enlarged 

 fangs ; mandibular teeth subequal. Head scarcely distinct from 

 neck; snout very short, projecting, cuneiform; rostral very large, 

 trihedral, with sharp A-shaped edge, produced posteriorly in a 

 narrow branch separating the internasals ; eye moderate, with round 

 pupil. Body subcylindrical ; scales slightly oblique, smooth, with 

 apical pits, in 19 or 21 rows ; ventrals obtusely angulate laterally. 

 Tail short ; subcaudals in two rows. 



Southern parts of South America, east of the Andes. 



Synopsis of the Species. 



Eye usually separated from the labials 



by a series of suboculars ; scales in 



21 rows ; ventrals 131-147 ; tail 



pointed 1. dorhigmji, p. 151. 



Eye in contact with two labials ; scales 



in 19 rows ; ventrals 133-144 ; tail 



pointed 2. Tiistricus, p. 152. 



Eye in contact with two labials ; scales 



in 21 rows; ventrals 153-173; tail 



rounded off at the end 3. semicinctus, p. 153. 



1. Lystrophis dorhignyi. 



Heterodon dorbignyi, Dum. ^ Bibr. vii. p. 772 (1854) ; Giinth. Cat. 



p. 83 (1858) ; Jan, Arch. Zool. Anat. Phys. ii. 1863, p. 221 ; 



Hensel, Arch. f. Nat. 1868, p. 329 ; Jan, Icon. Gen. 48, pi. iii. 



figs. 3 & 4 (1876) ; Boettg. Zeitschr. f. ges. Naturw. Iviii. 1885, 



p. 233. 

 Lystrophis dorbignyi, Cojje, Proc. Am. Philos. Soc. xxii. 1885, p. 193. 



