Prof. H. G. Seeley on the rnWiosaurian Pelvis. 249 



extremities of the bone is 1^ inch. The bone is thicker 

 and less bent on the left side than on the right side. 



Finally, Dr. Zittel has published a figure which shows the 

 interior of the pelvis, with the prepubis extending as'a bar imme- 

 diately in front of it (fig. 10), though, as in other specimens, 

 its contours are not perfectly displayed. This fossil appears to 

 prove that there is no articulation for the prepubic bone such 

 as was found by v. Quenstedt, and identified possibly in 

 harmony with the figure of Pt. dubius. Hence the facet may 

 have a pathological interpretation. No specimen has shown 

 a facet on the anterior margin of the pubis for articulation 

 with the prepubis ; and therefore the only position left for its 

 articulation is the anterior ventral margin of the pubic bone, 

 where there is often a suggestive correspondence in thickness 

 between the extremity of the pubic bone and the diameter of 

 the shaft of the prepubic bone. The extremity of the united 

 pubis and ischium in Zittel's specimen is manifestly imper- 

 fect, as shown by the pelvis referred by Wagner to Rh. 

 longimamis ; but there is some evidence that the ischia met ia 

 the mesial line in species of the Rhamphorhynchidse. 



Fiff. 11. 



Dimorphodon macronyv. 



From a specimen in the British Museum. 

 Nat. size. 



Another piece of evidence as to the structure of the pelvis is 

 furnished by Dimorphodon macronyx (fig. 11). The ilium is 



