8. LEPIDOSIERNON. 467 



than the latter, aud 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 ; 

 au aunulus 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, the largest only a little longer thaa 

 broad. Prseanal segments sis (rather irregular). Lateral liue 

 strongly, vertebral and ventral lines feebly marked. Yellowish 

 inferiorly, pale brownish above, without spots. 



raillim. 



Length to vent 350 



Tail 20 



Diameter of body IG 



Argentine Kepublic. 



«. Ad. Corrientes. 



12. Lepidosternon affine. 



Lepidosternum affiue, Boettg. Zeitschr.f. Naturw. Iviii. 1885, p. 233. 



Allied to L. (/ucntheri, 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. Eight 

 anal segments. 



Length to vent 294 millim. ; tail 16 millim. 



Paraguay. 



13. Lepidosternon boulengeri. 



Lepidosternum boulengeri, Buettg. Zeitschr. f. Naturw. Iviii. 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 praefrontal and supraocular, which 

 are fused into a single shield, its posterior sliglitly convex border in 

 contact with the pari(;tals ; a pair of occipitals, twice as broad as 

 long ; eye more or less distinct through the trapezoid ocular ; two 

 or throe temporals, ui)per large ; two \\\i\Mi.x lal>iaLs, first twice 

 as h)ng us second ; mental four-sided, followed by an elliptic 

 anteriorly truncate chin-shield; two lower labials, first twice as 



