Cope.] ^'^^ [Sept. 17, 



the largest scales. Three or four median rows faintly keeled on tlie pos- 

 terior Ihreefourlhs tlie length of the body. Muzzle sublruncate ; eye 

 large, its horizontal diameter equal tiie distance from its anterior border 

 to the posterior border of the rostral plate. Rostral plate sligiitly visible 

 from above ; internasals subquadrate ; prefrontals wider than long. 

 Frontal shorter than superciliaries, with concave lateral borders ; as wide 

 at the middle as a superciliary. Parietals as wide as long, and regularly 

 rounded in posterior outline. Nasal part of the nasoloreal plate witii the 

 superior and inferior borders parallel ; the superior border posterior to the 

 nasal part, sloping downwards to a subacute angle with the inferior bor- 

 der, which is in contact with the wide preocular. The latter barely 

 reaches the frontal on one side, and fails to do so on the other. Postoculars 

 two, the superior larger and half bounded posteriorly by the parietal. 

 Temporals 2-2 ; the interior anterior temporal in contact behind with the 

 parietal. Superior labials eight, the last very long on both sides, and 

 probably consisting of two plates fused. Fourth, fifth and sixth plates 

 bounding orbit, the seventh a horizontally placed parallelogram. Infe- 

 rior labials 12-13, much divided anteriorly, the posterior six all longer 

 than deep. Geneials elongate, the posterior pair longer. Gastrosteges 

 209 ; anal 1 ; urosteges 134. Total length 450 mm. ; length of tail 125 

 mm. ; length of head to rictus oris 20 mm. 



The ground color of the upper surfaces of this snake is a rich yellowish 

 brown. On the narrow dorsal region is a median series of parallelogi-am- 

 mic spots of an iron-rust color, each of which has a small blackish spot 

 at its anterior extremity. On the sides are wide vertical spots of iron-rust 

 color, which are of equal width with the length of the dorsal spots, and 

 which sometimes coincide with the latter, forming with them broad cross- 

 bauds. The chin and throat are cream-colored, but this color becomes 

 clouded, first with light, then with darker brown, and then with rusty 

 red with blackish specks, till the middle line of the abdomen posteriorly is 

 a dark mahogany. Opposite each vertical lateral bar is a dark spot on the 

 upturned extremity of the gastrostege. These become darker posteriorly, 

 forming subquadrate mahogany spots. Immediately below them a wide 

 pale border further varies the colors of the abdomen. A dark-brown 

 band passes to the neck posterior to the eye, and three descend from the 

 eye across the upper lip. Top of head rich yellowish brown, with a ma- 

 hogany spot on the posterior part of the prefrontal common suture, the 

 posterior part of the frontal, on the middle of each parietal, and 

 on the posterior external border of each parietal. Loreal region mahog- 

 any. Black spots on the anterior and middle inferior labial plates. 



Buenos Ayres, one specimen, No. 340. This is a handsome species, 

 whose colors are well calculated to conceal it on tree trunks and branches 

 where rusty colors predominate. In general character they are a good 

 deal like those of the Amastridium vcUferum of Veragua. 



