556 REPORT OF NATIONAL MUSEUM, 1898. 



shielded part ot lieiid, -SA mm.; head to posterior edge of ear, 8i mm.; 

 liead to auterior giihir fohl, 7^ mm.; head to posterior edge of anterior 

 fold, 11.^ mm.; head to posterior edge of posterior fold, ll'f mm. 



The single specimen of A^ f/ilbertii has been compared with 144 of 

 A'. vi<)ilis without any approach to any of its distinctive characteis hav- 

 ing been found. It is of great interest, for it extends the known range 

 of the genus Xantusia several hundred miles to the southward, intro- 

 ducing it for the first time into Mexican territory, and affording another 

 link between the "Cape region" and the Sonoran subprovince. 



Type. — Cat. No. 401, Cal. Acad, Sci. ; San Francisquito, Sierra Laguna, 

 Lower California; Gustav. Eiseu, March 28, 1892. 



TEIID^. 



Lacertiens, Scincoidiens Cuvier, part, Regne Anim., II, 1817, pp. 24, 61. 

 Tupinamhida', Chalcididie Gray, part, Ann. Phil, (2), X, 1825, pp. 199, 204. 

 Cordyloidea, Tachiidromoidea, Chalcidoidea, Ameivoidea Fitzinger, part, Neiie 



Classif. Kept., 1826, p. 11. 

 Teiidw Gray, Phil. Mag. (2), II, 1827, p. 55. 

 Autarchoglossa; acrodonta and pleurodonfa Wagler, part, Syst. Amph., 1830, pp. 



153, 154. 

 Ameiv(e, Lacertce, Chama'saitri, Ptychopleuri, Gymnoplithalmi Wiegmanx, part, 



Herpt. Mex., 1834, pp. 8, 9, 11. 

 Lacertiens pleodontes, Chalcidiens, Sc'nicoidiens Dumeril and Bibrox, part, Erp. 



GeD., V, 1839, pp. 68, 318, 511. 

 Teida; Chalcidcf, Anadiadw, Chirocolidw, Cercosauridw, Gymnophthalviidee Gray, 



part, Cat. Liz., 1845, pp. 3, 4. 

 ArgaUadce Gray, Ann. Mag. Nat. Hist., XVIII, 1846, p. 67. 

 Ecpleopoda Tschudi, Arch. f. Nat., 1847, p. 41. 

 lUamidw Gray, Proc. Zool. Soc, 1858, p. 445. 

 Cercosauri Peters, Abh. Berl. Acad., 1862, p. 169. 



Teida', Chalcidida', Ecpleopida' Cope, Proc. Acad. Nat. Sci. Phila., 1864, pp. 228, 229. 

 Teidce, Chalcididcc Cope, Proc. Amer. Assoc. Adv. Sci., XIX, 1871, p. 237. 

 Teiidee Boulenger, Ann. Mag. Nat. Hist. (5), XIV, 1884, p. 120. 



The following description, with slight modifications, is from Boulenger : 



The tongue is flat, more or less elongate, ending in two long smooth points, the 

 greater part of its surface covered with rhomboidal, imbricate scale-like papilhe ; 

 iu Alopoylossa, these scale-like papilhe are replaced by oblique plicio, as in Xautus- 

 siidiK and the Lacertoid genus Tachydromus. In a few genera the tongue is particu- 

 larly long and narrow at the base, which is retractile into a sheath ; in the others 

 the tongue is bicuspid posteriorly; the whole organ, when the distal points are 

 close together, being arrow-headed. 



The teeth vary considerably, but are constantly to be distinguished from those of 

 the analogous family Lacertidiu iu not being hollow at the base, the new teeth 

 developing iu small sockets at the base of the old ones. In some of the higher 

 forms (Tupinambis, Dracaena, Tei us), the lateral teeth are inserted almost on the 

 parapet of the Jaws, so that, in fact, they might be termed acrodont; this dentition 

 is, like that of the "pleurodonf Amphisbaiuoids, truly intermediate between the 

 acrodont and pleurodont. In the other forms the teeth are attached more distinctly 

 to the inner side of the jaws and there is a basal shaft. The priemaxillary teeth are 

 constantly conical ; the laterals may be conical, bicuspid, tricuspid, obtuse, or molar- 

 like (adult Tupinambis), or enormous oval crushers {Draccena); the bicuspid teeth 



