Dr. J. E. Gray on the African Trionyces with hidden feet. 441 



synonymous), as it has small white dots on its head, while C. frena- 

 tus, as its name implies, and C. Aubryi, as its figure shows, are not 

 spotted, and have black lines on the side of the head and neck. 



Cyclanosteus Petersii and Aspidochelys Livingstonii have been de- 

 scribed from shells of adult animals only, without any remains of the 

 bodies attached to them ; so that it is not possible to know whether 

 either of them be the adult form of Emyda senegalensis, or what is 

 the colouring of their head, which is a very distinctive character in 

 the animals of this family. 



Cyclanosteus frenatus is known'only from a note which Dr. Peters 

 sent home in 1848, shortly after his return from Mozambique. 



Cryptopus Aubryi is well described and figured by M. Dumeril in 

 the Rev. Zool. for 1856, p. 374, t. 20, and it appears to be very 

 nearly allied to the shield which I have lately described and figured 

 in the * Proceedings ' of the Society, under the name of Aspidochelys 

 Livingstonii (A.N. H. p. 68) ; but we cannot be certain that the animal 

 from Gaboon and that from Mozambique are identical, until we know 

 what are the peculiarities of the head of the Mozambique species. I 

 may state that Mr. Cope, in the ' Proceedings of the Academy of 

 Natural Sciences of Philadelphia ' for 1859 (p. 295), has formed M. 

 A. DumeriFs species into a genus, under the name of Heptathyra, 

 in which he evidently intended to include my genus Aspidochelys. 

 As his paper was read in 1859 and mine in 1860, his name ought 

 to have priority, unless it should be found desirable, as there is a con- 

 siderable difference between them in the form of the sternal callosities, 

 to preserve both the names. 



The African species known in their adult stage may be arranged 

 thus : — 



A. Sternal callosities 9 ; hinder pair small. 



1 . Cyclanosteus. The hinder pair of callosities very small, and 



far apart. 



C. Petersii, Gray, Cat. Tortoises, B.M. 65. t. 29. Gambia. 



B. Sternal callosities 7; hinder p air large. 



2. Heptathyra. The hinder pair of callosities rhombic, united 



together by their whole inner edge. 



II. Aubryi, Dum. Rev. Zool. 1856, 364. t. 20. 



Neck with three black streaks, the lateral ones from the eye ; oc- 

 ciput with two short black streaks. Gaboon. 



3. Aspidochelys. The hinder pair of callosities oblong, united 



by their hinder edge only. 



A. Livingstonii, Gray, P. Z. S. 18(50, 6. t. 22. River Zambesi. 



The only specimen of the Senegal species yet known to me is very 

 young ; it does not show the sternal callosities, and has still remains 

 of the umbilical slit. It may be described as follows : — 



Ann. is Mag. N. Hist. Ser. 3. Vol. vi. 29 



