192 ME. n. G. SEELEY ON OSSEOUS RESEMBLANCES 



more compressed from side to side at tlie distal end, and its proxi- 

 mal end usually curves backward. 



There are many points of difference in detail (in the metatar- 

 sals and phalanges), but nothing inconsistent with both having 

 had a primitive plan in common. 



§ 4. The CJielonian Characters of Lizards. 



There is no community of character in the skull, or vertebral 

 column, or pectoral girdle, beyond such features as all reptiles 

 have in common. 



In the humerus of Emysaiira, however, are found all the 

 points of the lacertian humerus ; only they are exaggerated to 

 an extent which might be considered grotesque. 



In the OS pubis of ZTromastix and the Dragon the prepubic 

 angle is prolonged into a digital process similar to that of a 

 Chelonian. The ischium of Einysaura is similar to that of Iguana. 

 But there seems to be in the ilium of Lizards always an angular 

 process in front above the acetabulum, of which Chelonians give 

 no indication. 



The characters of the Lizard femur, like those of the humerus, 

 are burlesqued by Emysaura ; and a new character is added 

 by the development of a great trochanter. 



The tibia and fibula would correspond very well with Mmysaura 

 but for the greater stoutness of the bones in the Chelonian. 



The tarsus corresponds generally ; and the bones of the Emy- 

 dian digits may be matched by those of the White Skink. 



§ 5. The Serjpent-characters of Lizards. 



The parietal in Iguana sometimes has a median ridge approxi- 

 mating to that 0^ Python. The squamosals in Serpents are always 

 prolonged backward ; but in Lizards the parietals are prolonged 

 with them and over them. The nares of both are divided by a 

 single premaxillary. The orbits are similarly vertical. The 

 pterygoid bones are very similar in their forms and in their con- 

 nexions with the quadrate, transverse, basisphenoid, and palatine 

 bones ; and in Iguana they are similarly divided from each other 

 mesially. The palatine bones of Serpents, like those of Hatteria, 

 carry teeth, and similarly abut against the maxillary, and similarly 

 are divided by the vomer ; but in the Boa the palatine is a nar- 

 I'ow bone 



