EAST AFRICAN REPTILES AND AMPHIBIANS 15 



Family PELOMEDUSIDAE 



Genus PELUSIOS Wagler 



PELUSIOS SINUATUS (Smith) 



Sternothaerus sinualus Smith, 1838, Illustr. Zool. S. Africa, Kept., vol. 3, pi. 1 

 (South Africa "in rivers to the north of 25° S. latitude). — Botjlenger, 

 1889, Cat. Chelon. Brit. Mus., p. 194.— Siebenrock, 1909, Zool. Jahrb, 

 supp. 10, pt. 3, p. 556. 



1 (U.S.N.M. 40253) Juja Farm, K. C. (Mearns) 1909. 



2 (U.S.N.M. 63379-80) Ujiji, T. T. (Raven) 1920. 



I have not the sHghtest doubt that these tortoises have been cor- 

 rectly identified with sinuatus; they agree in every respect with 

 Siebenrock's revised description. The mesial notch and lateral cusps 

 of the beak are certainly not obvious, but these characters — on which 

 Boulenger partly based his key to the species — are probably not of 

 specific importance, as has been suggested by various writers. I 

 hesitate to refer them to Hewitt's P. s. zuluensis, though they agree 

 with that race in the pronounced protuberances of the third and 

 fourth vertebras; they disagree in that their ventrals are broader 

 than long (as in sinuatus typica), but Hewitt's type series shows 

 great variation in his particular character and I attach no importance 

 to such variations. Siebenrock has already placed Boulenger's S. 

 lottegi from Zululand in the synonymy of sinuatus and the holotype 

 of hottegi was distinguished by very elongated vertebrals and by the 

 absence of the mesial notch and lateral cusps to which I have already 

 referred. Turtles and tortoises appear to be subject to a very wide 

 variation, and large series alone will help us to define the range and 

 limits of variation in this and allied forms. The young of sinuatus 

 and nigricans castaneus are very distinct, the former having the pos- 

 terior marginals with pronounced indentations so that the carapace 

 presents a sawhke or toothed edge posteriorly. The many score of 

 castaneus which I have handled have the sutures of the plastral 

 scutes black, sometimes only the center of the scutes showing any 

 light color; in sinuatus, however, the whole of the center of the plas- 

 tron is light (orange or yellow in life), only its outer edges being 

 margined with black. Whether this is the case with full-grown 

 specimens I am unable to say. The above series are all young, their 

 dimensions being as follows: 



