NATURAL SCIENCES OF PHILADELPHIA. 53 



of choanae. Skin rather smooth, especially on the head. No posttympanic 

 or antepectoral fold. No thoracic aggregation of cr/ptae ; paratoids flat, small. 

 Palmation of posterior digits extensive ; cuneiform process prolonged longi- 

 tudinally. 



Dimensions. Total length 5" 3"' ; from end of muzzle to behind tympanum 

 19'" ; of anterior extremity 3 // ; of posterior b" 9 //V . 



Above yellowish olive, with numerous defined brown bands and spots, which 

 have a general longitudinal direction, and cover more surface than the ground 

 color, A spot across each eyelid, one beneath the eye, one on the end of 

 the muzzle. Extremities marbled ; beneath olivaceous yellow. 



Habitat. Cape St. Lucas, Lower California. Mus. Smithsonian, (No. 5893;) 

 Philada. Academy. From John Xantus, E;q. 



S. rectifrenis Cope, sp. nov. 



Outline of maxillae acuminate-oval ; muzzle prominent, truncate in profile, 

 superior face decurved. Canthus rostralis strong ; loreal region plane, nearly 

 vertical. Frontal region plane, its width one-third the length of the tibia. 

 Tympanum concealed. Vomerine fasciculi closely approximate, posterior to 

 hinder margin of choanae. Skin of head and body sparsely tuberculous. A 

 weak antepectoral fold. Paratoid9 rather lateral ; no thoracic cryptae. 



Dimensions. From muzzle to vent 1" 8'"; from muzzle to brachiura 14 /// ; 

 length of anterior extremity 15 /// ; of posterior 3". 



Coloration. Above brown, or brownish-gray, the tubercles tipped with brown. 

 A brown line extends from each eye to sacrum, converging posteriorly. Side3 

 brown marbled posteriorly ; a short brown band from tympanum. Below light 

 yellow or brownish. 



Habitat. Tamaulipas, (Smithsonian, No. 3715.) Coahuila, (3714.) 



S. bombifrons Cope, sp. nov. 



Outline of maxilla? acuminate-oval ; muzzle truncate, elevated, thickened 

 transversely; profile of vertex arched, of front concave; canthus rostralis re- 

 placed by a concavity. Tympanum concealed or scarcely visible ; paratoid 

 flat, small. No gland on tibia or pectus. Tongue entire. Vomerine teeth iu 

 oblique fasciculi or short series between choanal ; these equal ostia pharyngea. 

 Skin nearly smooth, roughest on the sides. Cuneiform process produced. 

 Palmation of toes deeply repand. 



Dimensions of a tf. From end of muzzle to vent 4" 2"'; same to behind 

 tympanum 1" 5 ,// ; length of anterior extremity 19"'; of posterior 4" 6'". 



Color in spirits : pale ashen or brown, with numerous plumbeous vermicula- 

 tions, which are aggregated into a blotch on the scapular region, which has a 

 pale space below it. Limbs vermiculated ; outer border of tarsus and foot 

 light. A dark spot on canthus rostralis. 



Habitat. Fort Union, on Missouri River, lat. 48 N., from Mr. E. J. Denis, 

 (Smithsonian, No. 3704.) On Platte River, 200 miles west of Fort Kearney, 

 from W. S. Wood, of Lieut. Bryan's Expedition, (Smithsonian, No. 3520.) 

 Llano Estecado Texas, Capt. Pope's Exped. Coll., (Smithsonian, No. 3703.) 



This species has the most northern range of those found west of the 

 Mississippi. 



S. hammondii Baird, Report Surv. for Pac. R. R.. v. x. Lieut. Abbot's 

 Rep., pt. iv, p. 12, pi. XXVIII. f. 2. 

 Maxillary outline acuminate-oval ; muzzle somewhat truncate, perpendicular 

 in profile. Region of canthus rostralis concave ; front plane or a little concave, 

 with a weak ridge on each side, which is most distinct posteriorly ; the width 

 one-fourth length of tibia, and less than from no.-tril to lip. Eyes prominent; 

 tympanum distinct, one-fourth the extent of the former. A fold b -hind angle 

 of mouth. Paratoids flat, small ; no gland on tibia or pectus. Tongue very 

 large, entire. Choame large; vomerine teeth in transverse series between them. 

 Skin roughly tuberculous, especially on the sides ; thick on the occiput ; below 

 nearly smooth. Cuneiform process produced. 



1863.] 



