6 
published in the ‘Monatsberichte der Berliner Academie,’ 1854, 
p- 614, and which is reprinted in Wiegmann’s Arch. 1855, p. 43. 
Under these circumstances, as I applied Dr. Peters’ name Cyclanos- 
teus to the animal from the Gambia, and first gave the character to 
that genus derived from that species, and, as my description of that 
genus appears to be the only one that has been published, I think 
that the name Cyclanosteus must be retained for the Gambian Tor- 
toise, although probably Dr. Peters in his note intended it to refer to 
the Mozambique form. If I do so, the reference to Dr. Peters’ 
MS. must be erased from my account of the animal in the papers 
above referred to, and I must give a new name to the genus, to be 
established on the Tortoise from the Zambesi. 
This genus may be considered in some respects intermediate 
between Cyclanosteus and Emyda; for, though it has the simple 
flexible boneless hinder margin of the dorsal shield of the former 
genus, it has the seven sternal callosities of the latter ; but these cal- 
losities, though they agree in number, are of a much smaller size, 
compared with the size of the animal, than those of the genus 
Emyda. 
It is the giant of the group, agreeing in size and development with 
the genera of this family, which have the legs exposed, and especially 
with the genera Trionyx and Chitra. 
ASPIDOCHELYS. 
Head ? Limbs —~—? The hinder margin of the dorsal 
disk expanded, flexible, without any bony plates. The sternum 
broad, rounded before and behind, hiding the feet, with very distinet 
moveable flaps over the hinder feet. Sternal callosities 7, the odd 
one behind the oblong anterior pair, lunar, transverse, the hinder 
pair large, oblong, only united together on the hinder part of the 
mner margin. 
Hab. Africa. 
ASPIDOCHELYS LIVINGSTONI (Pl. XXII. fig. 1, 2). 
? Cyclanosteus frenatus, Peters, MSS. in Gray, Cat. Shielded 
Reptiles Brit. Mus. p. 64. 
Hab. Mozambique in tributaries of River Zambesi? (Dr. Living- 
stone). 
The dorsal shield is 22 inches long and 17 inches wide over the 
convexity of the back. 
. 
3. On THE Motuvusca or S1am. By Dr. Epvuarp von Martens. 
(ComMUNICATED BY Dr. A. GUNTHER, FoREIGN MEMBER.) 
During my stay in London I have had the opportunity of exa-- 
mining several collections of Siamese shells made by Sir Richard 
Schomburgk, J. C. Bowring, Esq., Dr. Harland, and Mr. Mouhot. 
