348 PROCEEDINGS OF THE ACADEMY OF 



Tkamnodynastes nattereri Wagler, Dam. Bibr., vii. p. 1149. (Braz.) 



This species was taken swimming in the river, near Assuncion. Its aspect 

 is not very dipsadine ; perhaps it should be removed, with the Phrynonax 

 1 unula t us,* to the neighborhood of Hypsirhynchus and Tomodon. Boie 

 more nearly expressed its affinities in calling it a Tropidonotus than others 

 have who denominate it Dipsas. 



Xenodon ?severus Boie, Erp. Gen., vii. 756. Nos. 5798-9. (Braz.) 

 Heterodon d'orbignyi Dum. Bibr., 1. c. vii. 772. No. 5808. 

 Helicops leprieurii Dum. Bibr., 1. c. vii. 750. Giinther, Ann. M. N. H., 

 1861, p. 427. No. 5400. (Braz.) 



Dimades plicatilis Gray, Dum. Bibr., 1. c. vii. 344. No. 5802. (Braz.) 



Opheomorphus meremmii Fitz. 



Var. semiaureus Cope, of a yellowish brown, the scales and head 

 plates without black borders. Abdomen yellow, gastrosteges dark-bordered 

 posteriorly ; gular and labial regions bright yellow. No. 4665. 



Opheomorphus doliatus Cope, Synopsis Holocosus and Ameiva, &c. 15. 

 Liophis doliatus Reinhardt, Herpetologiske Meddelelser, p. 14. 



Scales in nineteen rows. Var. sublineatus Cope, Proc. Acad. Nat. Sci. 

 Philada., 1860, 252. No. 4666. Var. csesiu s Cope. Light leaden brown, 

 the scales black bordered ; temporal regions black ; head plates black 

 bordered. Short irregular transverse brown lines on the dirty white abdo- 

 men. Superior labials white. Trace of a lateral black band on posterior 

 part of body and tail. Santa Fe. No. 5393. 



This serpent looks as though intermediate between the var. subline- 

 atus and O. meremmii of Brazil, and Liophis subfasciatus. Close 

 resemblance may be traced between the var. sublineatus and Lygophis 

 r u t i 1 u s. These species of the genus Liophis as formerly understood, are 

 in a very interesting condition somewhat better denned than the forms of 

 Herpetodryas, and more as in Xenodon, Thamnophis and Oxyrhopus. Careful 

 observation of such species must be of the greatest value in the demonstration 

 of the more difficult problems of natural science. 



Liophis subfasciatus Cope, Synopsis Holcosus and Ameiva, &c, p. 17. 

 No. 6310, 5S09-4-3. 



Lygophis r u t i 1 u s Cope, 1. c. p. 20. Buenos Ayres. No. 5397. 



Lygophis flavifrenatus Cope, 1. c. p. 20. No. 5398. 



Lygophis d i 1 e p i s Cope, 1. c. p. 21. No. 5861. 



Lygophis lineatus Fitz, Dum. Bibr., Erp. Gen., vii. p. 655. Nos. 5810, 

 6088. (Braz.) 



Pseudophis s c h o 1 1 i i Fitz, Dum. Bibr., 1. c. vii. p. 1118. (Braz.) 



A large specimen of this species (No. 5801) measures sixty-seven English 

 inches. A second species of Pseudophis is the P. patagoniensi s Cal- 

 lirhinus of Girard. 



Philodryas aestivus Gthr., Dum. Bibr., vii. p. 1111. No. 5812. (Braz.) 



Philodryas latirostris Cope, Synopsis of Holcosus and Ameiva, &c, p. 13. 

 The prtocular plates do not always reach the vertical in this species. 

 Scale pores single Nos. 5364, 5811. 



* Tropidodipsas lunnlata Cope, Pr. A. N. S. Philada., I860, p. 517, exhibits a union of 

 the peculiari'ies of tree and water snakes, and is the type of the genus Phrynonax, Cope. 

 The body is rather short, much compressed ; a few median rows of scales weakly keeled. 

 Anal plate entire. Scales biporous. Head distinct, broad, muzzle rounded. Two nasals, 

 one loreal, one preocular. Eye large, pupil round. Dentition isodont. Allied to Hyp- 

 sirhynchus. Diners from Spilotes in the long slender tail and broad depressed muzzle. 



[Sept. 



