Mr. P. L. Sclater on the Spur-winged Geese. 69 



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 distinct 

 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 

 inner margin. 



Hab. Africa. 



ASPIDOCHELYS LlVINGSTONII. 



? Cyclanosteus frenatus, Peters, MSS. in Gray, Cat. Shielded 

 Reptiles Brit. Mus. p. 64. 



Hab. Mozambique, in tributaries of River Zambesi? {Br. Living- 



The dorsal shield is 22 inches long and 1 7 inches wide over the \ 

 convexity of the back. . \ 



Further Evidence of the Distinctness of the Gambian 

 and Ruppeli/s Spur-winged Geese (Plectropterus gam- 



BENSIS AND P. RuPPELLIl). By PHILIP LuTLEY ScLATER, 



M.A., Secretary io the Society. 



The recent death of the males of the two species of Spur-winged 

 Geese {Plectropterus qambensis and P. Riippellii), of which I pointed 

 out the external differences at one of last year's meetings* of the So- 

 ciety, has given me the desired opportunity of comparing the tracheae 

 and skeletons of the two birds, and showing that these afford ample 

 corroboration of their specific distinctness. Before proceeding to do 

 this, I should remark that the individuals to be compared are both, 

 as we know from their dissection, adult males. The specimen of 

 P. gambensis is in all probability the older of the two, having been 

 living many years in the Society's Gardens. That of P. Riippellii 

 was received from Eastern Africa in June 1858. 



Comparing, first of all, the skulls of these two birds together, we 

 see that the frontal protuberance, which in P. gambensis (fig. 1) is 

 * See P.Z.S. 1859, p. 131. 



