No. 3.] PELVIS OF THE TESTUDINATA. 357 



but I think now that this opinion is not correct, and that 

 we have to adopt the view of Leydig, Fiirbringer, and Seeley, 

 that the ischium contains also the pubis, and that the free ele- 

 ments in front are not the pubes. If we study the ischium of 

 a Pterodactyl, we find that it forms a very broad plate, which is 

 firmly co-ossified with the ilium ; between these two bones the 

 acetabulum is placed. In the ischium we find, according to 

 Zittel {Handbuch dcr Palaeontologic, Vol. Ill, p. 786), a small 

 foramen below the acetabulum in Rhamphorhynchus and Dimor- 

 phodon. This foramen is said to be very much larger in Ptero- 

 dactyliis antiqiuis. In other species the " ischium " is divided 

 by the extension of this foramen into an anterior and posterior 

 branch. The bones called pubes are entirely excluded from the 

 acetabulum, and are connected with the anterior portion of 

 the "ischium." They are either separated from each other, 

 expanded distally, or united and slender, having on each side 

 a lateral process. I think that this condition can only be ex- 

 plained in this way : The foramen in the broad " ischium " rep- 

 resents the obturator foramen ; the pubis must therefore be 

 united with the ischium, of which it forms the anterior portion ; 

 the elements excluded from the acetabulum and connected with 

 the distal anterior end of the pubic portion of the ischium rep- 

 resent the cartilagines pyramidales. 



From this standpoint I think we have to look also at the 

 pelvis of the Crocodilia. It seems to be more probable to con- 

 sider the bone generally called ischium as the united pubis and 

 ischium ; the so-called pubis as the cartilago pyramidalis. Palae- 

 ontology has to decide this question. It is possible that the 

 triassic ancestors of the Crocodilia (the Aetosauria and Belo- 

 dontia do not belong here) will bring some light. In some of 

 the Dicynodonts we find the pubis greatly reduced, and it is not 

 unlikely that the pelvis of the ancestors of the Crocodilia will 

 show some resemblance to such a form. By this of course I do 

 not wish to express that the Dicynodonts are in any way related 

 to the Crocodiles. 



After having gone over the different groups of higher verte- 

 brates, we may now examine the history of the pelvis in the 

 lower types. Here I have little to add to the ontogenetic 

 researches of Wiedersheim, with whom I entirely agree in his 

 general results about the origin of the pelvis, which I can con- 



