8. LEPIDOSTERNON. 467 
than the latter, and broader than long; eye very distinct through 
the ocular; a large supraocular, followed by a nearly equal-sized 
upper temporal ; two upper labials, first large, second smaller than 
and under the ocular; mental small, four-sided, broader than long, 
followed by a large median chin-shield ; lateral chin-shields very 
small; two lower labials, first very large, second very small. Two 
hundred and forty-nine annuli on the body and twelve on the tail ; 
an annulus contains fifty-eight segments, thirty dorsal and twenty- 
eight ventral; the segments of the two median ventral series as 
broad as long or slightly broader. Pectoral shields numerous, 
small, forming oblique rows, tho largest only a little longer than 
broad. Przanal segments six (rather irregular). Lateral line 
strongly, vertebral and ventral lines fecbly marked. Yellowish 
inferiorly, pale brownish above, without spots. 
millim 
Length to vent .............. 350 
PAM: Sains giei aa Seonoeo eek ens 20 
Diameter of body ............ 16 
Argentine Republic. 
a. Ad. Corrientes. 
12. Lepidosternon affine. 
Lepidosternum affine, Boetty. Zeitschr. f. Naturw. viii. 1885, p. 233. 
Allied to ZL. guentheri, but differing in the following points :— 
Rostral apparently more pointed, as long as the first upper labial, 
with sharper edge; frontal hexagonal, forming an acute angle 
anteriorly and posteriorly ; occipitals thrice as broad as long; two 
upper labials, first much larger than second. Two hundred and 
sixty-six annuli on the body and sixteen on the tail; an annulus 
contains thirty dorsal and twenty-four ventral segments. Hight 
anal segments. 
Length to vent 294 millim. ; tai] 16 millim. 
Paraguay. 
13. Lepidosternon boulengeri. 
Lepidosternum boulengeri, Boetty. Zettschr. f. Naturw. viii. 1885, 
p. 220 
Snout rather pointed; frontal longer than broad, pyriform, its 
narrowed anterior extremity in contact with the rostral, its lateral 
edge forming a suture with the prefrontal and supraocular, which 
are fused into a single shield, its posterior slightly convex border in 
contact with the parietals ; a pair of occipitals, twice as broad as 
long; eye more or less distinct through the trapezoid ocular; two 
or three temporals, upper large; two upper labials, first twice 
as long as second; mental four-sided, followed by an elliptic 
anteriorly truncate chin-shield; two lower labials, first twice as 
