1865. ] DR. J. E. GRAY ON CYCLANOSTEUS. 427 
and Heptathyra to the exclusion of Peters’s genus Cycloderma and 
my own genus Aspidochelys. 
The synonyms of the genera stand thus :— 
I. The feet covered with flaps; the margin of the shield without 
any bones. 
Cyclanorbis, ‘ Peters, MS. 1848;” Gray, P. Z. S. 1852, p. 133. 
Cyclanosteus, Peters, MS. 1850 (type, C. frenatus). 
Cycloderma, Peters, Monatsb. 1854. 
This group includes— 
A. Callosities seven; head ovate. 
Heptathyra, Cope, Proc. Acad. N.S. Philad. 1859, p. 296 ; Gray, 
P. Z. 8. 1860, p. 315; 1864, p. 92. 
Aspidochelys, Gray, P. Z. S. 1860, p. 6. 
B. Callosities nine ; head depressed. 
Cyclanosteus, Gray, Cat. Shield Rept. B. M. 1855; P. Z. S. 1860, 
p- 315. 
C. Callosities four. 
Tetrathyra, Gray, P. Z.S. 1865. 
Since I have made out the history of these generic names, it has 
been suggested that I ought to have used Cyclanorbis and Cyclo- 
derma. I do not agree with that theory, as they were so defined as 
to include all the other forms ; while Cyclanosteus and Heptathyra 
accurately defined the species they each contained. 
It could make no difference to me, if I valued (as some zoologists 
seem to do), which I do not, having my name placed after a ge- 
neric name ; for in either case I should have established one genus, 
and another author the other; but I consider that a genus that is 
carefully and definitely characterized has a claim not to be put aside, 
and I think the following synonyma of the species will confirm my 
view of the case :— 
1. CyYCLANOSTEUS SENEGALENSIS. 
Cryptopus senegalensis, Dum. & Bibr. Erp. Gén. 505; Gray, 
P. Z. 8. 1860, p. 316 (junior). 
Emyda senegalensis, Gray, Cat. Tort. B. M. 47; Cat. Shield 
Rept. B. M. 64, 1855; P. Z.S. 1860, p. 316 (junior). 
Cyclanosteus petersii, Gray, Cat. Shield Rept. 64, t. 29, 1855; 
P. Z.S. 1860, p. 315. 
Cylanosteus senegalensis, Gray, P. Z. 8. 1864, p. 95. 
Hab. West Africa; Gambia. 
2. HEPTATHYRA AUBRYI. 
Cryptopus aubryi, A. Dum. Rev. Zool. 1856, p. 37, t. 20. 
