15, PanroDAcTYLus.—16. ARTHROSAURA. 389 
strongly imbricate, strongly keeled ; twenty-four to twenty-six scales 
round the middle of the body, including ventrals; thirty to thirty-four 
scales from occiput to sacrum inclusively. Ventrals large, in four 
large longitudinal series, passing gradually into the dorsal scales. 
Two pairs of large preanals, posterior largest. Limbs with large 
smooth shields; lower surface of arm and hinder side of thighs granu- 
late ; digits slightly, but distinctly, toothed inferiorly. Four femoral 
pores on each side in the males, one or two in the females. ‘Tail, 
when intact, extremely long, gradually tapering to a fine point; 
the scales similar to those of the body. Olive or brownish, above, 
sides darker; a light streak on each side, commencing above the 
ear; a more or less distinct dark vertebral line; lower surfaces 
whitish, more or less dotted with grey. 
millim. millim. 
Total length .......... 151 From end of snout to 
Head. ee ste see ae hese 9 WONG. piavuaaca es 39 
Width of head .......... 6 Fore limb seas cag ss ll 
From end of snout to fore Hindlmb .......... 16 
MIMD 6 48 Se arate a aos 15 Ma scenes ih tge oe ga ehavegee ee 112 
Southern Brazi], Uruguay, Buenos Ayres. 
a-c. 6,2,&yg. Rio Grande do Sul. Dr. v. Ihering fey 
d-g. 2 & yg. S. Lorenzo, Rio Grande do Dr. v. Ihering [C.]. 
Sul. 
Rs: Oe Brazil. 
7 Q. _Montevideo. 
k-l. 2 & her. Dept. of Soriano, Uruguay. R. Havers, Esq. [P.]}. 
m-p. Q@ & yg. Uruguay. 
16. ARTHROSAURA. 
Tongue moderately elongate, arrow-headed. Lateral teeth com- 
pressed, bi- or tricuspid. Head with large regular shields; fronto- 
nasal separating the nasals; preefrontals and frontoparietals present; 
nostril pierced in the middle of a single nasal. Eyelids developed, 
lower with a transparent disk composed of several scales. Har 
exposed. Limbs well developed, pentadactyle. Dorsal and lateral 
scales equal, hexagonal-lanceolate, keeled, imbricate, arranged in 
regular transverse series; ventral plates large, subquadrangular, 
rounded and overlapping posteriorly, smooth, arranged in regular 
longitudinal and transverse series. A collar fold. Tail cylindrical. 
Female without femoral pores.. 
Ecuador. 
This genus forms a connecting link between Prionodactylus and 
Heterodactylus. 
1. Arthrosaura reticulata. 
Cercosaura (Pantodactylus) reticulata, O’Shaughn. Proc. Zool. Soc. 
1881, p. 230, pl. xxii. fig. 1. 
Head depressed, snout short, obtuse ; body rather elongate. A 
