194 PKLOMEDUSIDJE. 



II. 8uiurc between the abdoininul shields shorter than that between 

 the humerals ; plastral hinge feeble. 



The length of the outer border of the pec- 

 toral shield equals that of the humeral . 5. adansonii, p. 196. 



The length of tlie outer border of tlie pec- 

 toral is less than that of the humeral . . 0. (jahonensis, p. 197. 



1 . Sternothaerus niger. 



Steraotiiicrus niger, Ihtm. c^ Jiihr. ii. p. 397, pi. xx. fig. 1 (1835) ; 

 Grail, Cat. Tort. ]). 37 (1841), and Sh. lt<'pt. i. p. 51 (1855), and 

 >Siippl. p. 81 (1870) ; rcters, Mon. Bcrl. yLc. 1875, p. 11)6. 



Steruotha3rus, sp., Grai/, Proc. Zool. Soc. 1873, p. 39-3, fig. 



Carapace with a feeble, interrupted keel. Plastral shields appa- 

 rently as in B. derbianus. Upper jaw strongly hooked, not notched ; 

 the width of the interorbital space is less than the longitudinal 

 suture between the two shields on the snout. Hhell black ; head 

 fulvous above, marbled with brown ; jaws yellowish, with vertical 

 brown lines. 



West Africa (Cameroons). 



a. Ad., skull. W. Africa. M. Dii Chaillu [C.]. 



2. Sternothsenis simiatus. 



Sternothajrus sinuatus, Smith, III. Zool. S. Afr., Bept. pi. i. (1838) ; 



A. Dum. Cat. 31cth. liept. p. 19 (1851) ; Grai/, Proc. Zool. >Soc. 



1803, p. 193, and Suppl. Cat. Sh. Eept. i. p. 78 (1870) ; Peters, Reise 



n. MosMimh. iii. p. 8 (18S:?). 



dentatus, Peters, Arch. f. Anat. u. P/n/s. 1848, p. 494. 



castaneus, Grai/, Cat. Tort. p. 37 (1844), and Sh. Eept. i. p. 52 



(1855). 



Carapace rather elongate, posterior margin more or loss serrated 

 or sinuated, except iu old specimens ; second and tliird vertebral 

 shitdds about as long as broad in the adult. Intergular sliield more 

 than twice as long as broad; suture between the abdominal shields 

 longer than that between tbe femorals ; the length of the outer 

 Ijorder of the pectoral shield is as great or a little less than that of 

 the humeral, and exceeds tbe length of tlie inner border of the latter 

 shield. Head moderate ; snout short ; upper jaw notched in the 

 middle, with a vcrj^ slight, rather indistinct obtuse cusp on each 

 side of the notch ; interorbital width less than the longitudinal 

 suture between the two shields on the snout. Carapace dark 

 brown or blackish ; plastron yellow or blackish ; head pale brown 

 above, with darker verniiculations. 



Length of shell 22 centirn. 



South Africa ; East Africa south of the E(]uator ; Seychelles. 



