266 Transactions. — Zoology. 



Endo-sTceleton. 



Skull generally much depressed, with thin bones. Dis- 

 tinct nasals. Jugal rudimentary, the orbit not being bounded 

 posteriorly by a long arch. No postfronto-squamosal arch. 

 Pterygoids widely separated, without teeth. A columella 

 cranii. Mandible of five bones, the angular and articular 

 having coalesced. 



Teeth pleurodont, small, numerous, closely set, with long 

 slender cylindrical shaft and obtuse point. The new teeth 

 hollow out the base of the old ones. 



Vertehrce amphiccelous. Eibs long, and so prolonged as to 

 form more or less ossified hoops across the whole abdominal 

 region. 



Limb-arches. — Clavicle dilated, perforated proximally. In- 

 terclavicle subrhomboidal to cruciform. Bones of the limbs, 

 including those of the digits, well developed. 



Mode of Beproduction. 



Most geckos are oviparous, producing round eggs with a 

 hard shell. The endemic New Zealand genera seem to be 

 quite exceptionally viviparous. 



Gymnodactylus, Spix. 



"Digits not dilated, clawed, cylindrical or slightly de- 

 pressed at the base ; the two or three distal phalanges com- 

 pressed, forming an angle with the basal portion of the digits ; 

 the claw between two enlarged scales (a superior and an 

 inferior), of which the inferior is more or less deeply notched 

 under the claw ; digits inferiorly with a row of more of less 

 distinct transverse plates. Body variously scaled. Pupil 

 vertical. Males with or without praeanal or femoral pores." 



The genus as defined ranges over Australia, the islands of 

 the Pacific, tropical America, the borders of the Mediter- 

 ranean, and southern Asia. 



Gymnodactylus arnouxii, A. Dum. 

 Gymnodactylus arnouxii, A. Dum., Cat. Meth. Eept., p. 44, 



and Arch. Mus., vii., p. 479, pi. xviii., fig. 5; Boulenger, 



Cat., i., p. 39. 



" In habit similar to G. pelagicus. Sixteen longitudinal 

 very regular series of round, convex, smooth tubercles. Abdo- 

 minal scales small, smooth. Tail with uniform small smooth 

 scales, forming rings. Nostril pierced between the rostral, 

 the first labial, and several nasals, the antero-superior of 

 which is enlarged; eight upper and seven lower labials; 

 mental very large, subtriangular, extending beyond the 

 labials ; a small chin-shield on each side of the mental. 



