624 



DR. R. BROOM ON 



on each side of ench vertebral spine. All the best preserved 

 scutes are about twice as long as broad and have the long axis 

 lying antero-posteriorly. 



Some at least of the ribs of the middle region of the body 

 appear to have uncinate processes. These are little ossifications 

 about 3 or 4 mm. in length and about 1 mm. in width. They 

 are firmly attached to the posterior side of the ribs but not 

 anchylosed. Just possibly, though much less probably, they are 

 small lateral dermal scutes. 



Befoi'e discussing the affinities of Euparkeria and the Pseudo- 

 suchians generally, it will be well to consider some points in the 

 structure of the allied genera from Elgin. These very interesting 

 specimens, preserved in the British Museum, reveal a few points 

 in the structure of the group not seen in the specimens of 

 Eii,2xirkeria, and afford a very thorough knowledge of the sub- 

 order. Aetosaurus ferratus, on which the suborder Pseudosuchia 

 was founded, has never been very thoroughly described, but 

 Mr. Watson assures me that there is no doubt that it has two 

 temporal vacuities like those of Euparlceria and Ornithosuchus, 

 and not one as described and figured by Fraas. Though there 

 is thus little doubt that AetosauriijS belongs to the same suborder, 

 it diff"ers in a good many points from the Elgin and South-African 

 forms. 



Ornithosuchus woodwardi Newton. (Pis. LXXVII.- 

 LXXIX., figs. 9, 10, 16, 25.) 



The type of this Pseudosuchian is a fairly complete skeleton from 

 Elgin, described in 1894 by Mr. E. T. Newton, The specimen is 

 preserved in the British Museum, and through the kindness of 

 Dr. Smith Woodward I have been enabled to make a fresh study 

 of it in the light of the new knowledge obtained from the allied 

 South- African form. Newton's study of the type has been so 

 thoroughly and carefully done that there is very little in the 

 specimen he has failed to observe, and the points where I incline 

 to differ from him are very few in number. Fortunately the 

 British Museum has recently obtained a second specimen which 

 supplies a number of blanks in our knowledge. 



The skull, on the whole, resembles that of Euparli-eria in all 

 essentials, so far as can be seen, though the cranial sutures are 

 less easily made oiit in OrnitJiosuchus and the palate is unknown 

 in Euparlceria. The skull of O^^niihosuchus woodioardi is more 

 slenderly built, and it differs in having apparently no inter- 

 parietal, in the shape of the jugal, in having a much larger 

 antorbital vacuity, and in having the teeth differently arranged. 

 In the restored side view of the skull which I give, and which 

 difffers only slightly from that given by Newton, the shape of 

 the various openings and bones can readily be seen. The dental 

 formula of Ornithosuchus appears to be i. 3, m. 9 as against 

 i. 3, m. 12 in Euparlceria; and there is the further difference 

 that, while in the South African genus only one mandibular tooth 

 overlaps the upper jaw-border, in Ornithosuchus thei'e are two 



