SCINCID^. VM 



usually consist of a transverse one anastomosiu}^ with several longi- 

 tudinal ones *. Head covered with syminelrical shields ; an azygos 

 occipital is rarely present. Pupil rouud. Eyelids well developed. 

 No femoral pores. 



Scincoids are cosmopolitan, the bulk occurring in Australia, the 

 islands of the Pacific, the East Indies, and Africa ; they are com- 

 paratively very poorly rei)resented in South America. As far as we 

 know at present, all sj)ecies are ovoviviparous. Adaptations to 

 every mode of life, save a(piatic and aerial, occur. 



I have met with great difficulty in arranging the genera of this 

 family. The majority of the characters hitherto employed for 

 the distinction of genera, such as the degree of development of the 

 limbs, the presence or absence of a transparent disk in the lower 

 eyelid, the presence or absence of keels on scales, &c., are in many 

 cases not even of specific value ; I have therefore used certain 

 characters which hitherto have been neglected, but which, I am 

 convinced, afford a firmer basis for a natural arrangement. The 

 artificial nature of an arrangement based on the degree of develop- 

 ment of the limbs has been pointed out by others f. In a family 

 like the Scincoids, in which the limbs are undergoing a process 

 of abortion, this character must be abandoned as one expressing 

 relationship by itself; and I trust that the arrangement of the 

 species in one or more series within a genus J, passing from forms 

 with weU-developed pentadactyle limbs and lacertiform physiognomy 

 to such as have rudimentary limbs, or even none at all, marks 

 a great improvement upon the artificial classifications in use down 

 to the present day. 



Synopsis of the Genera. 



I. Nostril pierced in the nasal, or between nasal and supra- or post- 

 nasal or first upper labial, not touching the rostral. 



A. Palatine bones separated on the median line of the palate 

 (fig. a, p. 132} ; no supranasal shields. 



No azygos occipital shield 1. Egernia, p. 134. 



An azygos occipital shield, in contact with the interparietal ; tail 

 prehensile 2, Corucia, p. 141. 



* The principal modiiications of this structure have been exquisitely figured 

 by Bocourt (Miss. Sc. Mex., Rept. pis. xxii. i. & xxii.^.). Owing to the great 

 amount of variation I have found within one and the same species, or difference 

 between otherwise closely allied species, I have liad to abandon the hope I 

 at first entertained of employing this character for the arrangement of the 

 genera in this family. 



t Cf. Gimther, Proc. Zool. Soc. 1871, p. 243. 



I As examples of genera with several diverging degradational series, the 

 genera Li/yoboma and Chalcides are recommended for study. 



k2 



