On the Families of existing Lacertilia. 117 



EXPLANATION OF PLATE V. 



Fiy. \. Lycopodifes Stockii, Kidston, n. sp., nat. size-, a, h, c, d,f. Sporan- 

 gium-like leaves (?) ; e. Reniform sporangia of terminal cone. 

 Fig. 2. Leaf, enlarged, seen on fig. 1, g. 

 Fig. 3. Sporangium-like leaf (?), enlarged, seen on fig. 1, a. 

 Fig. 4. Smnll portion of stem, enlarged, showing leaf-cicatrices. 

 Fig. 5. Li'pidvdendron rimosum, Sternberg. 



XVI. — Sr/nojjsis of the Families of existing Lacertilia. 

 By G. A. BOULENGEE. 



Whilst engaged in a revision of the Lizard-collection in the 

 British Museum, I have felt the necessity of a thorough syste- 

 matic rearrangement of the order Lacertilia. The classitica- 

 tions proposed by Dumeril and Bibron and Gray, and now 

 still generally in use, with slight modifications, are, on the 

 whole, as unnatural as can be, and founded to a great extent 

 on characters of pholidosis and physiognomy. Physiognomy 

 is worth nothing as a guide in the formation of higher groups ; 

 as to the characters afforded by the scales I have convinced 

 myself that they are very deceptive, and ought to be taken 

 into consideration in the definition of families only when 

 accompanied by other characters. Like Cope, whose lizard- 

 families* I regard as the most natural hitherto proposed, I 

 shall lay greater stress on osteological characters and on the 

 structure of the tongue. Special importance must also be 

 attached to the presence or absence, and the structure, of 

 dermal ossifications on the head and body, and these will be 

 found to correspond with many other characters. Bocourtf, 

 to whom is due the merit of having pointed out their syste- 

 matic importance, did not realize the very great progress 

 made by means of that character, the modifications of which 

 he so ably illustrated, for he still maintains the artificial 

 group Scincoidiens, in spite of the objections of Cope, whose 

 views are evidently confirmed by the researches of tlie French 

 herpetologist. 



The order Lacertilia, as restricted by Giintlier %, may be 

 divided into two primary groups only, the Chameleons on 

 the one hand, and all the other Lizards on the other. The 

 Amphisbffinians, which by nearly all recent authors are sepa- 



* Proc. Acad. Pliilad. 18G4, p. 224, and Proc. Am. Assoc. Adv. Sc. 

 xix. 1871, p. 236. 



t Mission Scient. Mexique, Rept. p. 470 (1881). 

 t Phil. Trans. Roy. Soc. clvii. 18(i7, p. 625. 



