540 Mr. R. W. Ilooley on the 



Dorsal Vertebr<2. 



Seeley * classifies these vertebrae into two groups by tlie 

 same cliaracteristics. He gives as examples those figured l)y 

 Owen t ill liis memoir on Pterodactylus sedyioicki. There is 

 no justification for Owen assigning either the cervical to 

 P. simus or the dorsal to P. sedgwicki, nor for Seeley the 

 flat cervicals to Ornithocheirus. The characters pertaining 

 to any particular genus cannot yet be definitely given. 



The Notarium. 



Bones which in Ornithosauria were included in the sacrum 

 and the os innominatum^ and numbered and figured respec- 

 tively 



J. c. 4, 1. Ornithosauria. PI. x. Figs. 8, 9. 

 J. b. 10, 3. do. PI. viii. Fig. .3. 



by the discovery of the blending of the early dorsal vertebra; 

 into the so-called notarium of the American form Pteranodon, 

 were found to belong to this portion of the axial skeleton. 

 Owen J described and figured a bone from the Cambridge 

 Greensand which belongs to the notarium as " probably 

 frontal,''^ The specimen J. c. 4, 1 was figured in the restora- 

 tion of the pectoral girdle by Seeley in 1891 § and 1901 \\. 

 Both of these diifer in detail from the original vertebra which 

 is figured in Ornithosauria. Prof. Willistou ^ has pointe 1 

 out that the vertebra of these figures is "undoubtedly 

 wrong.^' 



It would, perhaps, be safe to assign to Oniithostoma all 

 the specimens belonging to the notaiium, because we have 

 the Araeiican evidence of its obtaining in Oniithostoma 

 {Pteranodon), while there is none as regards the dentigerous 

 jaws from Cambridge. 



The Sacrum. 



The six specimens of sacral vertebrte are so destroyed that 

 it is impossible to say whether the transverse ribs weie 

 anchylosed at their distal extremities as in Ornithostonia 

 [Pteranodon). Nos. 1 and 2 have the ventral surface of the 



* PI. G. Seeley, ' Ornitliosanria,' 1870, p. 01). 



t R. Owen, liep. Cret. Form. (Mon. J'til. 8oc. IS.jO), Suppl. i. pi. ii. 

 fjg.9. 20 & 23, and fig-s. 24 & 2o. 

 J Id. ibid. p. 12, pi. iv. figs. 0-8. 



§ IL(;. Seeley, Ann. Si Mag. Nat. Illst. (6) vol. vii. i). I II, fig. 2(1891). 

 II Id. ' Dragons of the Air,' lUOl, p. llo. 

 U S. W. Williston, Kansas Univ. (^lart. 1897, p. 14. 



