300 ANNIELLID^. HELOUERMATID^. 



six) round the middle of the body, No enlarged anal scales. Tail 

 ending obtusel}', when intact measuring one third (or two fifths) 

 of the total length. Silvery, the scales edged with brown ; a 

 narrow brown vertebral line. 



Prom snout to vent 130 millim ; tail 60. 



California. 



a. Ad. California. Sir J. Richardson [P.], (Type.) 



2. Anniella nigra. 

 Anniella nigi-a, Fischer, Ahh. nat, Ver. Ilamb. ix. 1885, p. — .* 



Twenty-eight scales round the body. The three median anal 

 scales twice as long as those preceding. Black above, yellowish- 

 white interiorly. Otherwise as in A. indchra. 



San Diego. 



Fam. 11. HELODERMATID^. 



Thecoglossse pleurodontes, part., Wagler, Syst. Amph. 1830. 

 Trachydermi, Wiec/mami, Herp. Mex. 18.35. 

 Varaniens, part., TJumeril 4' Bihron, Erp. Gen. iii. 1836. 

 Helodermidse, Gray, Prvc. Zool. Soc. 1837, and Cat. Liz. 1845. 

 Helodermidse, Cope, Proc. Ac. Philacl. 1864 & 1866. 

 Trachydermi glyphodonta, Bocourt, Miss. Sc. Mex., Rept. 1878. 

 Helodermatidte, Boulenyer, Ann. Sf May. N. If. (5) xiv, 1884. 



Tongue villose, the anterior portion smooth, bifid, protractile. 

 Dentition resembling that of the Ophidia, the teeth being fang-like, 

 with slightly swollen base, rather loosely attached to the inner edge 

 of the jaws; the teeth grooved in front and hehind (JleJ ode rma) ; 

 teeth on the pterygoid and palatine bones. Praemaxillary single ; 

 nasals and frontals double ; prae- and postfrontals in contact, sepa- 

 rating the frontal from the orbit ; a strong postorbital arch ; no 

 postfrontosquamosal arch ; parietal single ; pterygoids and palatines 

 widely separated ; infraorbital fossa bounded by the pterygoid, 

 palatine, transverse bone, and maxillary. Head with bony tubercles. 

 Eyelids well developed. Limbs well developed ; clavicle slender ; 

 interclavicle without transverse processes ; sternum divided longi- 

 tudinally. Skin of upper surfaces tubercular, some of the larger 

 tubercles ossifying in the adult, of lower surfaces forming transverse 

 Beries of squarish plates. No femoral or praeanal pores. 



The genus Heloderma, the only poisonous Lizard at present 

 known, is very closely related to the Anguidce, but well deserves to 

 rank as a distinct family, on account of certain cranial peculiarities 

 and the shape of the interclavicle. Its range is restricted to the 

 western parts of Central America, from tlie Isthmus of Tehuantepec 

 to as far north as New lEexico. 



Quoted from an advanced sepai'ute copy. 



