ivTEW LlZAllD OF fHE GENUS CHALCIDES. 899 



40. Description of a New Lizard of the genus Chalcides, 

 from the Gambia^ living in the Society's Gardens. 

 Bj E. G. BouLENGER, F.Z.S. (Curator of Reptiles). 



[Received October 5, 1922 : Eead November 7, 1922.] 



The Society recently received from H.E. Capt. 0. H. Armitage, 

 C.M.G., a generous donor to its collection, a number of reptiles 

 from the Gambia. Among these was a Lizard of the genus 

 Chalcides which is evidently undescribed, and for which I 

 propose the name of Chalcides at^mitagei, after its discoverer. 



Chalcides armixagei, sp. n. 



Snout more conical than wedge-shaped, but with distinctly 

 projecting labial edge. Eye small. Ear-openings not larger 

 than the nostril, on a line with the mouth. Nostril pierced 

 mostly in advance of the suture between the rostral and the 

 first labial. Supranasals united. Frontal longer than broad. 

 Fourth labial entering orbit. Body very elongate. Sides of 

 body not distinctly angular. Scales perfectly smooth, in 24 rows 

 round the middle of the body. Limbs short tridactyle. Length 

 of hind-limb not quite equal to distance between eye and fore- 

 limb. Fore-limb equals in length distance between, posterior 

 border of orbit and snout. Tail shorter than head and body. 



From snout to vent 119 millim. ; tail 82 mm. 



Great variation is to be found in the structure of the Lizards 

 of the genus Chalcides, especially in the proportions of the limbs 

 and body, and in the number of digits, where we find all stages 

 of degeneracy, there being species with five, four, three, or even 

 tAvo fingers or toes. A linear arrangement based solely on the 

 number of the digits would be imnatural, as 1 have attempted to 

 show in a recent paper*. The shape of the snout, whether 

 conical or wedge-shaped, is of importance in tracing lines of 

 descent; this character being also taken into consideration, the 

 species here described as new cannot be placed in the group 

 Ch. sjihenopsiformis, delislii, and sepoides, its position being 

 intermediate between Gh. viionecton (with four fingers and toes, 

 and 24 or 26 scales round the body), and Ch. mauritanicus (with 

 two fingers and three toes, and 10 scales round the body). 



* P.Z.S. 1920, vol. i. p. 77. 



