GASTORNITHIDJ.. 359 



Genus DASORNIS, Owen '. 



Known by the cranium, which difl'ers from tliat of Gasfomis hy 

 the more backward position of the postorbital process, and the con- 

 sequently shorter temporal fossa and longer orbital region. In 

 this respect the genus occupies the same position in regard to 

 Gastoi-nis as is held by Striithio to the Dinornithidce. The occipital 

 condyle is more nearly s])heriral and relatively smaller than in 

 Gasfoniix. 



Dasornis londiniensis, Owen-. 



The type and only described species. The skull is of nearly the 

 same dimensions as that of Pachyomis elepliant02nis. 

 Hah. Europe (England). 



31929. The imperfect posterior portion of the cranium ; from the 

 (Fiij.) London Clay of the Isle of Sheppey. The type and only 

 known specimen. Described and figured by Owen in the 

 ' Trans. Zool. Soc' vol. viii. p. 145, pi. xvi ; noticed by 

 Seeley in the ' Quart. Jouru. Geol. Soc.' vol. xxx. p. 710, 

 where it is conjectured that it may be the skull of Megal- 

 ornis (see p. 47) if it really belong to a bird and is not 

 the skull of a fish. Compared with the figure of the 

 skull of Gastofiiis edwardsi given by Lemoine in his 

 * Eecherches sur les Oiseaux Fossiles des Environs de 

 Reims,' pt. ii. pi. ix. (Paris, 1881), the resemblance between 

 the contracted and concave frontal region of the two speci- 

 mens is so close as to leave little or no doubt as to the near 

 alliance of their respective owners. The process marked 

 12 iu fig. 4 of Owen's plate clearly corresponds to the 

 postorbital process (AP in Lemoine's figure). Whether 

 the cranial sutures were persistent in this genus cannot 

 be determined. The more expanded occipital region of 

 the present specimen, as compared with Lemoiiic's figure 

 of Gastornis, may be at least partly due to the imperfection 

 of the specimens from which the latter was drawn. 



Apart from its resemblance to Gastornis, this skull is 

 proportionately far too large to have belonged to Argill- 

 ortiis. Purchased. 



' Proc. Zool. Soc. 18(>V1, p. ."lO. This name being derived rroni canos. is not 

 preoeenpied by Dasi/'irnif, Vig»r.<! and Horsfield, 1S2(5. - Lcc. cif. 



