ANGUlDiE. 265 



Fam. 9. ANGUID^. 



Ophisauroidea, part., Chalcidoidea, part., Anguiuoidea, Fitzinger, 



Neue Classif. Hcjjt. 182(). 

 Autarclio<rlossa3, part., Waylcr, Syst. Amph. 1830. 

 Ptycliopleuri, part., Scinci, part., Wieymann, Ilerp. Mex. 18o4. 

 Chalcidiens, part., Sciucoidieiis, part., Dumeril i^- Bihron, Erp. Gen. 



V. 18:3U. 

 Zoiiuridfe, part., Scincida?, part.. Gray, Cat. Liz. 1845. 

 Anguidse, Gerrhonotida3, Cope, Proc. Ac. rhilad. 1864. 

 Anguida3, Boulenyer, Ami. 1^- May. N. H. (5) xiv. 1884. 



The tongue is composed of two distinct portions : a principal 

 posterior, thick, covered with villiform papillae ; and a small anterior, 

 thin, emarginate, covered with Icpidoid imbricate papillie, extensible 

 and more or less retractile into a sheath formed by a transverse fold 

 at the anterior extremity of the villose portion. This retractility of 

 the distal part of the tongue appears to be constant, though more 

 accentuated in some species than in others * ; but it shoiild be borne 

 in mind tliat when the tongue is fully extended, every trace of the 

 transverse fold or sheath disappears, which accounts for the seeming 

 exceptions presented by spirit-speciiuens in that condition. 



The dentition varies from the strictly pleurodont tubercular teeth 

 of Ophisaurus apus and some BiplofjJossi, through the conical teeth 

 of the majority of species, to the curved fangs of Anguis. The 

 dentition of the latter has no other equivalent but that of Heloderma, 

 to which it bears considerable resemblance ; and Leydig has even 

 discovered the presence of a slight groove along the anterior surface 

 of the teeth which appears to be homologous with the anterior groove 

 of the poisonous Lizard's fangs ; the teeth of Anguis are likewise 

 remarkable for the comparatively feeble attachment to the jaws, as in 

 Heloderma and the Snakes. The new teeth do not hollow out the 

 base of the old ones, but originate between them. The palate is 

 either toothless, or teeth may be developed on the pterygoids or even 

 on the palatines and vomers [Ophisaurus). 



The skull belongs to the normal Lacertilian type. The pra3- 

 maxillary is single ; nasals distinct ; frontal single in GerrJionotus, 

 double in the other genera ; parietal single ; palatines and ptery- 

 goids well separated along the medial line ; infraorbital fossa 

 bounded by the palatine, pterygoid, transverse bone, and maxillary. 

 Dermal cranial ossifications are ])resent, which roof over the supra- 

 temporal fossa. The limbs may be more or less developed, or 

 entirely absent externally, in which case, however, the rudiments of 

 the pectoral and pelvic arches are always present. The clavicle is 

 slender, and the intcrclavicle, in the species with well-developed 

 limbs, cruciform. Abdominal ribs are absent. 



The body is protected by bony plates underlying the scales, which 



* The coiimidii ,Slo\v-«oiiii iiiii\ be hikcii as* a fair exauiplc, sliuniiig this 

 elructure develupeil to a niodoi-aU- degree. 



