224: CHELTDIDiE. 



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 lilack ; 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 nock, passing through the eye ; another 

 parallel 1 •lack 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 s])ots or interiupted longitudinal bands ; limbs 

 olive, yellowish on the inner side. 



Length of shell 25 centim. 



Brazil. 



a-c. § «&. ligr., spir. Eio Grande do Sul. Dr. v. Iheiing [C] 



4. Hydraspis gibha. 



Emvs gibba, Sclmeiyg. Proch: p. 30 (1814). 



? EuiYS radiolata, Wml, Ahhild. pis. — (1831). 



? Platemys radiolata, Lmn. l*)- Bibr. ii. p. 412 (1835), 



Platemys gibba, Bum. ^ Bibr. p. 416, pi. xx. tig. 2. 



? Platemys miliusii, Bvm. ^- Bibr. p. 431. 



Hydraspis gibba, Gray, Cat. Tort. p. 40 (1844), and iS/i. BejA. i. 



p. 55 (1855). 

 ? Phiynops ? miliusii, Gray, Cat. Tort. p. 42. 

 Hydraspis nasuta, Gray, Cat. Sh. Bept. i. p. 55. 

 ? ilydraspis miliusii. Gray, I. c. p. 50. 

 Hydraspis gordoui, Gray., Broc. Zovl. Soc. 18G8, p. 663, pi. xVn.jand 



Sttppl. Cat. Sh. Bept. i. p. 74 (1870). 



bicolor. Gray, Ann. c^ May. N. 11. (4) xi. p. 304 (1873). 



Mesoclfmmys gibba, Gray, I. c. p. 305. 



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 iippcr surface of head divided 

 into irregular shields ; parietal bones above wider than the diameter 

 of the orbit ; mental barbels shorter than the (hameter of the eye. 

 Uniform dark chestnut-brown above ; marginal yellow interiorly ; 

 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. S , stffd. Mt. Tamana, Trinidad. (Type of H. gordotii.) 



b. Yg., 8]dr. Demerara Falls. (Type of JI. bicolor.) 



c. $, stttd. ? 



d. Yp-., spir. ? 



