1. TKIONYX. 255 



Stml p. 175 (18G2), and Verth. SehihJki: p. 12G (18U5) ; BoeWj. 



Ber. i>'emk. Ges. 1879-80, p. 208 (1880). 

 Trionvx iiiloticiis, Gray, Syn. liept. p. 4G (1831), and Cat. Sh. Rept. 



i. p' 08 (1855). 

 Gyniiiopus ajjn-ptiftciis, 7)h?«. l^- Bihr. ii. p. 484 (1835). 

 Triouyx labiatus, Bill, Tcst.'^h. — (1837). 

 Tyi-se nilotica. Gray, Cat. Tort. p. 48 (1844), and Proc. Zool. Soc. 



18G4, p. 88, a7id SnppL Cat. Sh. Rept. i. p. 108 (1870), and Ann. 



(§• May. N. 11. (4) xi. p. 470 (1873). 

 Trionyx mortoni, Hallow. Proc. Ac. Philad. 1844, p. 120. 

 Aspidouectes aspilus, Cvpe, Proc. Ac. Philad. 1859, p. 295. 

 Fordia afiicana, Gray, Proc. Zool. Sue. 18G9, p. 2 J 9, and Suppl. Cut. 



Sh. Rept. i. p. 100, and Proc. Zool. Soc. 1873, p. 4'-), (igs. 

 Trionyx triucguis, Peters, Mon. Berl. Ac. 1870, p. 117. 



Costal plates eight pairs, the last well developed and in contact 

 throughout on the median line ; a single neural between the first 

 pair of costals ; dorsal plates coarsely pitted and vcrmiculate. Dor- 

 sal skin of young with longitudinal ridges of small tubercles. 

 Epiplastra widely separated, the anterior branch short ; entoplas- 

 tron forming a right or acute angle ; plastral callosities well deve- 

 loped in the adult, hyo-hypoplastral and xiphiplastral, and coarsely 

 sculptured like the carapace. Head small; snout (on the skull) 

 much longer than the diameter of the orbit ; interorbital space, in 

 the adult, at least as broad as the nasal fossa ; postorbital arch not 

 half the diameter of the orbit ; mandible without symphysial ridge, 

 its width at the symphysis equalling or exceeding the diameter of 

 the orbit. Olive above, closely spotted and speckled with whitish 

 in the young ; throat and lower surface of shell with round white 

 spots separated by a dark network ; adult more uniform. 



Length of dorsal disk 80 centim. 



Africa (Nile, Congo, Senegal, and intermediate water-systems) 

 and Syria. 



Dr. T. Christie [P.]. 

 T. Thornton, Esq. [P.]. 

 Zoological Society. 

 Dr. Riippell [C.]. 

 Consul I'etherick [C.]. 

 (Types of Fordia africana.) 

 Consul Petherick [C.]. 

 Zoological Society, 

 Dr. Baikie [C.]. 

 M. Du Cliaillu [C.l. 

 M. A. Linden [C], 

 Dr. Bailde [C], 

 G. Malcolm, Esq. [P.J. 

 J. J . Monteiro, Esq. [P.], 



