176 IGUANIDE. 
small pouch on each side of the throat. Sides of neck irregularly 
folded, with groups of small spinose scales. A small dorsal crest, 
most developed on the nape. Dorsal scales small, rhomboidal, im- 
bricate, keeled, ending in a spine, obliquely directed towards the 
vertebral line; lateral and ventral scales as large as dorsals, latter 
smooth. The adpressed hind limb reaches the shoulder, or between 
the latter and the ear. Tail roundish, with serrated upper ridge ; 
caudal scales larger than dorsals. Upper surfaces olive, lighter- 
dotted, with ill-defined dark brown crescentic cross bands; sides 
bluish; antehumeral fold black; lower surfaces yellowish, throat 
clouded with blackish. 
millim. millim 
Total length ...... 284 Fore limb.... ... 59 
Head). vecnwaw seis 28 Hind limb........ 80 
Width of head .... 25 Tail (reproduced) .. 150 
BOY vacua gages 106 
Paraguay ; Argentine Republic. 
a-b. 3. Paraguay. 
ed 3. Cosquin, Cordova. E. W. White, Esq. [C.]. (Types of 
Letocephalus variegatus.) 
7. Tropidurus torquatus. 
Taraguira torquata, Gray, Cat. p. 220. 
darwinii, Gray, J. ¢. 
Stellio torquatus, Wied, Reise n. Bras. i. p. 139. 
Tropidurus torquatus, Wied, Beitr, Nat. Bras. i. p, 137, and Abbid. ; 
Reinh. §& Liitk. Vidensk. Meddel, 1861, p. 227; Peters, Mon. Berl. 
‘Ac. 1877, p. 409. 
Agama tuberculata, Spiz, Spec. Nov. Lacert. Bras. p. 12, pl. xv. fig. 1. 
Ecphymotes tuberculata, Guér. Icon. R. A., Rept. pl. xii. fig. 2. 
torquatus, Dum. §& Bibr. iv. p. 344. 
Tropidurus microlepidotus, Fitzing. Syst. Rept. p, 72. 
Taraguira torquata, Girard, U.S. Explor. Exped., Herp. p. 318. 
Upper head-scales smooth ; a series of transversely enlarged supra- 
oculars, the width of which never exceeds half the width of the 
supraocular region ; occipital usually longer than broad, and nar- 
rower than the supraocular region ; temporal scales flat and feebly 
keeled ; a fringe of long scales in front of the ear. A strong, 
slightly curved antehumeral fold, widely separated from its fellow ; 
one or two more or less marked transverse gular folds ; sides of neck 
granular, with one or two oblique folds or pouches. No dorso- 
nuchal ridge. Dorsal scales small, slightly larger than ventrals, 
keeled, rhomboidal, imbricate, and ending in a short spine in the 
males, subhexagonal in the females and young; keels of the dorsal 
scales forming oblique lines; ventrals smooth. The adpressed hind 
limb reaches the ear or the eye. Tail once and one fourth to once 
and a half as long as head and body, round or slightly compressed ; 
caudal scales much larger than dorsals, ending in a spine. Olive or 
brownish above, usually with darker spots and lighter dots ; usually 
a more or less distinct light and a dark lateral dorsal band; a black 
