182 REPORT OF NATIONAL MUSEUM, 1898. 



was Latreille. In 1825, in bis Families Natiirelles du Regue Animal, 

 he separated the Squamata, under the name Squamosa, from the tor- 

 toises and crocodiles, on account of the slight fixity of the quadrate 

 bone, the double male intromittent organs, and the structure of the 

 feet. He was followed in this after a long interval by Stannius, who 

 in 1856 reviewed the Squamata under the name of Strep tostylica,' 

 including in it the two orders Sauria and Ophidia. I adopted this 

 name as that of a superorder in 1871,^ including in it the Sauria and 

 Ophidia, and a third order, the Pythonomorpha, which I had already 

 proijosed in 1869 for the mosasauroid reptiles. This arrangement was 

 retained in a synopsis of the families of Vertebrata published in 1889,^ 

 except that the term Squamata was employed instead of Streptostylica, 

 and was applied to an order instead of a superorder. This arrangement 

 is continued in the present work. Dr. Boulengcr has adopted this 

 system, but added the chameleons, or Rhiptoglossa, to the list of orders, 

 increasing the number to four. This change is not adopted in the pres- 

 ent work. The solidarity of the order Squamata is attested by the 

 reproductive system as well as by the osseous, and especially by the 

 characters of the male intromittent organ, as I have recently pointed out. 



SAURIA. 

 I. ANATOMY. 



1. OSTEOLOGY. 



The following summary of the osteology of the Sauria is based on 

 examinations of the specimens contained in most of the museums of 

 Europe and of this country. For North American forms I am princi- 

 pally indebted to the United States National Museum, my private 

 collection, and that of the Academy of Natural Sciences of Philadel- 

 phia. The characters observed during my study of material in Europe, 

 which I found to be of the greatest taxonomic importance, I enumerated 

 in a paper which is printed in the Proceedings of the Philadelphia 

 Academy for 1864, p. 224. The use then made of those characters has 

 been generally accepted by subsequent writers.^ There are, however, 

 many other characters whose value is of uncertain taxonomic value, 

 which were not then mentioned, and which I now record. 



The first description of the osteology of the Sauria is that of Cuvier, 

 which is contained in his Ossemens Fossiles.'' This is an excellent 

 one, but the many types discovered since his time render it neces- 



' Siebold unci Stannius, Handbuch der Zootomie, Berlin. 



-Proceedings, American Association lor the Advancement of Science, XIX, p. 233. 



'American Natnralist. See also Transactions, American Philosophical Society 

 1892, On the Osteolo-,'y of the Sknil of Keptilia. 



^See Boulenger, Ann. Mag. Nat. Hist., XIV, 1884, p. 117; and Catalogue of Lizards 

 in British Museum, I, 1885; II, 1885; III, 1887. This author has added osteological 

 characters of the EublepharidiCj Uroplatidas, PygopodidaJ, and Dibamidse. 



fi Volume X, edition of 1836. 



