6. CYCLANORBIS. 271 



the costals meeting on the median line and separating the neurals 

 from each other; eighth pair of costals largo. Plastron with a 



Fig. 73. 



ISkull of Cyclanorbis scneyakii6i6. (_From Gray, P. Z. S. 1854.) 



cutaneous femoral valve, under which the hind limb may be con- 

 cealed ; hyoplastron coossified with hypoplastron ; nine or more 

 plastral callosities in the adult, a pair being present in front of, and 

 ossifying independently from, the epiplastrals. Bony choanaj 

 between the orbits ; jaws strong ; postorbital • arch moderate, nar- 

 rower than the diameter of the orbit ; posterior border of pterygoids 

 with a median ascending process forming a suture with the opis- 

 thotic. 



Tropical Africa. 



1. Cyclanorbis senegalensis. 



Crj^jtopus senegalensis, Dum. 8f Bibr, ii. p. 504 (1835). 



Emyda senegalensis, Gray, Cat. Tort. p. 47 (1844), a)id Sh. Rept. 



i. p. 64 (18oo). 

 Cyclanorbis petersii, Gray, Proc. Zool. Soc. 1852, p. 135. 

 Cyclanosteus petersii. Gray, Proc. Zool. Soc. 1855, p. 201, and Cat, 



Sh. Rept. I. p. 64, pi. xxix. 



