CKOCODILIANS, LIZARDS, AND SNAKES. G25 



Lampronaurus Hallowei.l, I'roc. Acad. Nat. Sci. Phila., 18.")2, p. 206. 

 Eiirylepis Blvth, Jouru. Asiat. Soc. Beng., XXIII, 18.54, p. 739. 

 Mahonia Gunther, Proc. Zool. Soc Lonil., 18(50, p. 31(5; Kept. Brit. Ind., 1864, 

 p. 82. 



Nostril pierced iti the nasal plate. Palatine and pterygoid bones 

 separated on the median line of the palate, the latter with teeth. Supra- 

 nasal plates i)resent. Limbs pentadactyle, the digits not denticu- 

 lated laterally. 



The preceding characters define a natural genus. The following are 

 also common to the species: The nostrils are lateral. The postnasals 

 vary. There are either one or two; if the latter, one may be directly 

 above the other, or the second may be both behind and above the first. 

 The head is covered with ossified plates concealing the muscles and 

 with an external epidermis. The tongue is thick, elongate, cordate or 

 arrow shaped, slightly notched anteriorly, and quite homogeneously 

 squamous throughout. The flap covering the anus is margined behind 

 by two large plates, with smaller ones on either side. 



Osteology. — For the determination of the skeletal characters of this 

 genus I have skeletons of the i^\ obsoletus and U. quinquelineatus from 

 the national collection. 



The premaxillary is split as in other Sciucidfe, and the halves are in 

 the closest contact. The common spine is rather elongate, while the 

 palatal suture is simply emarginate. The nasals are not shortened, and 

 are distinct. The frontal is double, and is simply grooved on the mid- 

 dle line below. The parietal is single, and is i)ierced by the pineal 

 foramen at about its middle. The parietoquadrate arch is well elevated. 

 The supraoccipital is loosely articulated, presenting a truncate median 

 process toward, but not to, a median notch of the i^arietal. Exoccip- 

 tals distinct by suture. Prefrontal rather large, not sending poste- 

 riorly a supercilliaiy process, and not produced far above the orbit. 

 Lachrymal small; not, or very little, visible on external facial surface, 

 and reached by a long internal process of the jugal. External surface 

 of jugal separated widely from prefrontal, its i)ostorbital portion much 

 longer, slender, and rising to meet the postfrontal. The latter is large 

 and unequally V-shaped, the posterior limb broad and covering the tem- 

 poral fossa between the parietal and supratemporal bones, with more 

 or less of a fissure next the parietal posteriorly. Postfrontal a si)lint 

 separating the jugal and supratemporal from the postfrontal. Supra- 

 temporal well produced anteriorly, and in contact with the parieto- 

 qiuKlrate arch for tlie posterior two-thirds the length of the latter. 

 Quadrate with one, a deep external, conch. The vomers are elongate, 

 and also expanded laterally, passing above the prominent palatine 

 lamina' of the maxillary, bones. They are in close apposition on the 

 median line, but are so swollen longitudinally as to leave a groove at 

 the common suture. The longitudinal ribs terminate in a pair of 

 appressed hooks, which look downward and backward at the posterior 

 extremities of the bones. The vomerine branch of the palatine is not 

 NAT MUS 1)8 40 



