NATURAL SCIENCES OF PHILADELPHIA. 78 



well developed ; superior preoculars not reaching vertical, the inferior want- 

 ing on one side. Superciliaries very narrow. Two postoculars. Superior 

 lahials nine, fifth and sixth entering the orbit. Ten inferior labials. Scales 

 in seventeen rows, rather lanceolate medially. Total length 23 in. 9 lin ; the 

 tail 9 in. 8 lin., rather more than two-fifths. Ground color red. This is 

 crossed on the body by nineteen black rings, which leave it in spaces of only 

 a scale in width above, and one to three gastrosteges beneath. On the head 

 the ground only appears as a spot on the second and third labials, one on the 

 middle of each superciliary, one near the anterior angle of the vertical, and 

 one on the common occipital suture ; also a band extending from the seventh 

 and eighth superior labials posteriorly to the occipitals. Anterior and pos- 

 terior inferior labials black. Tail with eleven black rings broader than those 

 on the body. 



Hob. Region of the Truando, New Grenada. Mus. Smithsonian, (No. 4303,) 

 Lieut. Michler's Exploring and Surveying Expedition Coll. 



Philodryas latirostris. 



Muzzle obtuse, depressed, rather broad. Rostral shield elevated, rounded 

 above. Prefontals broader than long, postfrontals broad. Vertical narrow, 

 not twice as long as its anterior breadth, the lateral borders concave ; occipi- 

 tals not elongate ; temporals five, the anterior and largest narrow, in contact 

 with the whole posterior border of the inferior postocular. Preocular grooved 

 so as to appear divided, in contact with the vertical ; loral parallel sided ; 

 prenasal larger than postnasal. Eight superior oculars, fourth and fifth enter- 

 ing orbit, the posterior three as high as, or higher, than long. Pregeneials 

 longer than postgeneials. Scales smooth, in nineteen longitudinal rows. 

 Gastrosteges not angulated. Total length 3 in. 2 lin. ; the tail 6 in. 6 lin. 



Green, paler beneath, yellowish on the mental and superior labial regions. 

 A narrow black band from the eye along the borders of the upper labials. 



Hab. Paraguay. Mus. Smithsonian, (No. 5811,) Capt. Page Coll. 



This species has a broader muzzle than P. viridissimus Giinth. The 

 vertical plate is more elongate than in P. crassifrons Cope. From both 

 it differs in the contact of the latter with the preocular, and in the absence of 

 angulation of the gastrosteges. 



Ialtris yultuosa. 



Char. gen. Form elongate, principally on account of the development of the 

 tail. Head moderately distinct, a little elongate, rather massive. Eye mode- 

 rate, pupil round, The nine normal cephalic shields. Rostral normal, not 

 prominent. Two nasals, one loreal, one preocular. Anal plate divided. 

 Scales smooth, the pores double. Anterior superior maxillary teeth moderate, 

 equal, separated by a short space from an elongate stout grooveless tooth 

 which occupies a position half way between the extremities of the maxillary. 

 Posterior half of this bone edentulous, except a long grooved tooth at its 

 hinder extremity. Several anterior mandibulars long, stout, separated by a 

 space from the succeeding series of small ones. 



Char, specif. Scales not elongate, in nineteen longitudinal rows. Posterior 

 border of each postfrontal convex. Vertical twice as long as its anterior 

 breadth, the lateral borders a little concave, the posterior angle obtuse. Oc- 

 cipitals elongate, acuminate posteriorly, the common emargination acute 

 angled ; common suture as long as the vertical. Temporals, three large, one 

 small, on each side, the anterior in contact with the two postoculars, and the 

 fifth and sixth superior labials. One grooved preocular, one parallelogrammic 

 loreal, two nasals, the posterior higher. Rostral low, rounded above. Seven 

 superior labials, third and fourth entering the orbit, seventh longer than high. 

 Nine inferior labials, the fourth and fifth very large. Total length 45 in. 6 lin., 

 tail, 13 in. 6 lin. or -38 of the whole. 



The general color is leaden olivaceous ; the gastro and urosteges are bor- 



1802.] 



