798 SCIENTIFIC RECORD FOR 1885. 



Cope's work upon the group is indeed the only contribution to the taxon- 

 omy of the lizards that is esteemed of special value by the author of the 

 new catalogue. That author is the well-known herpetologist in charge 

 of the reptiles of the British Museum, Mr. George Alfred Boulenger. 

 Mr. Boulenger, however, by no means follows Professor Cope throughout, 

 but has his own well considered views as to the value of the characters 

 first brought prominently forward by Professor Cope. He accepts the 

 order of Lacertians with the limit generally accredited to it of late years, 

 and thus excludes the SphenontidsB or Hatteriidae. The order is sub- 

 divided into two sub-orders : (1) the Lacertilia vera ; (2) the Ehipto- 

 glossa. The several sub-orders into which the former have been disin- 

 tegrated by Professor Cope are not recognized and even the families 

 have in some cases been separated, by the intervention of groups adopted 

 by Professor Cope. Twenty-one families of the order are adopted by 

 Mr. Boulenger, and it is interesting to note that three of these were en- 

 tirely unknown to Dum6ril and Bibron when, in ^836 to 1839, they pub. 

 lished those volumes of their great work devoted to the order. 



The following tabular synopsis of the characters most made use of 

 by Mr. Boulenger will give an idea of the range of variation and system- 

 atic values of the various characters. The external form is found to 

 be not only of very little use, in many cases, in the determination of the 

 relations of the types, but sometimes it is very illusive indeed. 



The characters utilized for the diagnosis of the various families are 

 almost exclusively derived from the skeleton and teeth, and especially 

 from the cousideration of the following elements : 



1. The development or non-development of a post-frontal arch {Posffr.). 



2. The development or non-development of a post-orbital arch (Post- 

 orb.). 



3. The development or otherwise of a supra-temporal roof {Suprat. 

 roof). 



4. The existence or absence of a columella crani {Col. cr.). 



5. The development or non-development of an inter-orbital septum 

 (J. 0. s.). 



6. The number of parietal bones, *. e., whether paired or single {Par.). 



7. The number of frontal bones, whether double or coalesced (Fr.). 



8. The number of nasal bones, i. e., whether two or one {I^asals). 



9. The number of pre-maxillary bones, i. e., whether one or two pairs 

 (P. max.). 



10. The number of elements in each ramus of the lower jaw or man- 

 dible, i. c, whether four or five {Mand.). 



The teeth, especially whether implanted along the edge of the jaws 

 (acrodent) or on the inner slope (pleurodent) {Teeth). 



12. The development of inter-clavicles, i. e., whether "dilated" and 

 " loop shaped proximally," or whether "not dilated proximally " and 

 cruciform {X). Of course in forms whose fore limbs are absent or very 

 much reduced, the inter-clavicles are wanting? 



