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. Duméril 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. Duméril’s 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. 
Oo it African species known in their adult stage may be arranged 
us :— 
A. Sternal callosities 9 ; hinder pair small. 
1. Cycuanostevs. 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 pair large. 
2. Herrarnyra. The hinder pair of callosities rhombic, united 
together by their whole inner edge. 
H. 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. Asprpocnetys. The hinder pair of callosities oblong, united 
by their hinder edge only. 
A. Livingstonii, Gray, P. Z. S. 1860, 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. & Mag. N. Hist, Ser. 3. Vol. vi. 29 
