OPHIDIA. 55 



We subdivide them into two tribes. 



That of the Amphisb^n^j as in the preceding reptiles, still 

 has the lower jaw supported by a tympanal bone directly arti- 

 culated with the cranium, the two bunches of this jaw soldered 

 together in front, and those of the upper one fixed to the 

 cranium and to the intermaxillary bone, circumstances which 

 prevent that dilatation of the mouth which obtains in the suc- 

 ceeding tribe, and which occasions a uniformity of the head* 

 and body, a form w^hich enables them to move backwards or 

 forwards with equal facility. The bony frame of the orbit is 

 incomplete behind, and the eye very small ; the body is cover- 

 ed with scales, the anus close to its extremity, the trachea 

 long, and the heart very far back. They are not venomous. 



They form two genera, one of which is allied to Chalcides 

 and Chirotes, and the other to Anguis and Acontias. 



Amphisb^na, L.(1) 



The whole body surrounded with circular ranges of quadrangular 

 scales, like the Chalcides and the Chirotes among the Sauriansj a 

 series of pores before the anus, a few conical teeth in the jaws, but 

 none in the palate. There is but one lung. 



Two species have long been known, Amph. alba^ Lacep. II, 

 xxi, 1; and Amph. fuliginosa, L., Seb. II, xviii, 2, C. 3 and Ixxiii, 

 4, both from South America. They feed on insects, and are 

 often found in ant-hills, which has occasioned a belief among 

 the people that the large ants are their purveyors. They are 

 oviparous.(2) 



There is another in Martinique entirely blind, Amph. C3eca, 



Cuv.(3) 



The Leposternon, Spix, are Amphisbaenas, the anterior part of 



whose trunk has a collection of plates above which interrupts the 



rings. They have no anal pores, their head is short, and their 



muzzle somewhat elongated.(4) 



(1) From ct/ui<pic and Caivuv, walking both ways. The ancients attributed two 

 heads to it. This name has been erroneously applied to some American Serpents, 

 which it is impossible the ancients could have known. 



(2) The Amph. flavescens, Pr. Max. Lib. IX. 



(3) May it not be the d. vermicularis, Spix, XXV, 2? he says, "occuli viz con- 

 sptcui" — I can see none. He employed the same expression for his J. oxyura. 



(4) Lep. microcephalus, Spix, or Amph. punctata, Pr. Max. 



