224 CHELYDID@. 
the abdominals. Median region of upper surface of head divided 
into irregular shields ; parietal bones above wider than the diameter 
of the orbit; mental barbels as long as the diameter of the eye. 
Carapace yellowish brown above, closely striated or vermiculated 
with black ; plastron and lower surface of marginals olive or brown ; 
head olive above, marbled with black; a broad black band on each 
side of the head and neck, passing through the eye; another 
parallel black band along the upper lip and side of neck; throat 
and lower surface of neck yellow; a horseshoe-shaped black band 
on the chin, embracing the base of the barbels; lower surface of 
neck with black spots or interrupted longitudinal bands; limbs 
olive, yellowish on the inner side. 
Length of shell 25 centim. 
Brazil. 
a-c. 2 & hgr., spir. Rio Grande do Sul. Dr. v. Ihering [C.! 
4, Hydraspis gibba. 
Emys gibba, Schweigg. Prodr. p. 80 (1814). 
P Emys radiolata, Wied, Abbild. pls. — (1881). 
? Platemys radiolata, Dum. § Bibr. i. p. 412 (1835 »): 
Platemys g oibba, Dum: & Bibr. p. 416, pl. xx. fig: 2. 
id Platemys miliusii, Dun. § Bibr, p. 451. 
Hy draspis gibba, Gray, Cat. Tort. p. 40 (1844), and Sh. Rept. i. 
p. 05 (1855). 
? Phrynops ? miliusii, Gray, Cat. Tort. p. Be 
Hydraspis nasuta, Gray, Cat. Sh. Rept. 1. p. 6 
Y lly draspis miliusii, Gray, l. e. p. 56. 
Hydraspis gordoni, Gr ie Proc, Zool. Soc. 1868, p. 565, pl. xlii., and 
‘Suppl. Cat. Sh. Rept. 1. p. 74 (1870). 
bicolor, Gray, Ann. re Mag. N. H. (4) xi. p. 804 (1873). 
Mesoclemmys gibba, Gray, l. c. p. 505. 
Carapace with a vertebral keel, which becomes very indistinct in 
the adult. Front lobe of plastron not or but slightly broader than 
hind lobe; intergular shield shorter than its distance from the 
abdominals; suture between the pectorals shorter than that between 
the abdominals. Median region of upper surface of head divided 
into irregular shields ; parietal bones above wider than the diameter 
of the orbit; mental barbels shorter than the diameter of the eye. 
Uniform dark chestnut-brown above; marginal yellow inferiorly ; 
plastron dark brown, bordered with yellow ; head brown above, 
spotted with black; throat yellowish in the young, spotted with 
black ; barbels uniform yellowish. 
Length of shell 18 centim. 
Trinidad, Guianas, Brazil. 
a. 3, stfid. Mt. Tamana, Trinidad. (Type of ZZ. gordoni.) 
b. Yg., spir. Demerara Falls. (Type of ZZ. bicolor.) 
c. @, stffd. ? 
d. Yg., spir. —? 
