RHYTIDODEIRA OXYCEPHALA. 353 



Observ. — Not among the reptiles collected by the U. S. Exploring 

 Expedition. 



Log. — Republic of Chile. 



5. Rhttidodeira nigromaculata, Grd. 



Spec. Char. — Head short ; snout rounded and obtuse. Supralabial 

 plates quadrangular and well developed. Temporal scales large, 

 superiorly keeled, inferiorly smooth. Scales, on sides of neck, thick 

 and rhomboid; lateral and abdominal scales smaller than the dorsal 

 ones, and posteriorly emarginated. Posterior aspect of thighs wholly 

 granular. Tail rather short. Greyish-fawn, with two series of 

 angular black spots on each side ; a large scapular black patch ; 

 thighs posteriorly black-dotted. 



Syn. — Tropidurus nigromaculatus, WiEGM. in Nov. Act. Acad. nat. cur. XVII, i, 

 1835, 229. 



Proctotretus nigromaculatus, DuM. & BiBR. Erpet. gen. IV, 1837, 281. — Bell, Zool. 

 Voy. Beagle, V, 1843, 10. PI. iv, fig. 2.— Guich. in Gay, Hist, de Chile, Zool. II, 

 1848, 34.— DuM. Voy. Venus, Zool. 1855, 293. PL iir, fig. 1. 



Ptychodeira nigromaculata, FiTZ. Syst. Kept. I, 1843, 73. 



Liolaemus nigromaculatus, Gray, Catal. Lizz. Brit. Mus. 1845, 213. 



Rhytidodeira nigromaculata, Grd. in Proc. Acad. Nat. Sci. Philad. November, 

 1857, 198. 



Observ. — This species was not amongst those collected by the U. S. 

 Exploring Expedition, and hence, is here not further described. 



Log. —Republic of Chile. 



6. Rhytidodeira oxycephala, Grd. 



(Plate XXVIII, figs. 26-33.) 



Spec. Char. — Head very much depressed, rather short ; snout rather 

 narrow, though rounded off upon its periphery. Labial and supra- 

 labial plates narrow and elongated j supralabials smaller than the 

 labials. Auricular aperture large, granular in front. Temporal 



