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FOSSIL REPTILIA OF THE 



(ib. 3 ib., 25) ; this abuts by its outer end against the hinder end of the maxillary (ib., ib., 

 21 ) and the contiguous part of the malar (ib., ib., 26), the fore part of the pterygoid (24) 

 bounding with the ectopterygoid the hinder half of the ptery go -maxillary vacuity (y). The 

 fore part of the pterygoid, continued along the inner border of that vacuity, articulates 

 with the palatine (20), which, with the maxillary (21), completes the fore part of the 

 boundary of y. We have thus the homologue of the ' great palatal opening ' of Cuvier, 1 

 and of the ' posterior palatal opening ' of Eudes-Deslongchamps in the Teleosauras 

 cadomensis? which answers to the vacuity y in the Lacertians, figs. 6 and 7, PI. II. 



The medial pair of openings (PI. II, fig. 25, s, s), bounded externally by the 

 palatines and pterygoids, and internally, as it seems, by medial processes of the same 

 bones, answer to the 'fosse pterygoidienne' (vi) of Eudes-Deslongchamps in Teleosaurus 

 temporalis? and to the ' fosse nasale posterieure ' of Cuvier in the Teleosaurus cadomensis. 4. 

 But in Hylceochampsa this pterygoid fossa, or posterior nostril, is divided by so strong a 

 longitudinal bony bar that the pair of vacuities might be taken at first sight to answer to 

 the ' grands trous palatins ' in the Crocodilus rhomb if er. 5 



Such a determination is, however, incompatible with the coexistence of the vacuities 

 {y, y) in Hylceochampsa and the concomitant recession of the maxillaries (21) from the 

 outer boundaries of the openings( s , s, PI. II, fig. 25). 



We have thus another and most remarkable modification of the bony palate to add to 

 those which have led that acute observer Eugene Eudes-Deslongchamps to remark, in 

 reference to the extinct Crocodilia of the Caen Oolite and other Mesozoic localities, 

 " chaque espece presente des modifications particulieres." 6 



But although it maybe admitted that the pair of medial openings (fig. 25, s , s) answer 

 to the single medial opening (Cuv., t. c, PI. VII, fig. 4, «) in Teleosaurus, it does not 

 absolutely follow that they served in Hylceochampsa the office of palato-nares. It might be 

 contended that the small single orifice at the mid-line of the extreme hind border of the 

 bony palate (ib., e) fulfilled that function, as the similarly sized and situated orifice per- 

 forms in recent Crocodilia. The still smaller orifice (fig. 23, v) placed at the hind surface 

 of the skull might in that case be homologized with the median Eustachian outlet, 7 and 

 not with the vascular foramen, 8 in Crocodilus. 



It should, however, be borne in mind that the true hinder nostril in proccelian 



1 ' Ossemen's Fossiles,' torn, cit., p. 133, pi. vii, fig. 4, r. 



2 ' Notes Paleontologiques,' p. 139, pi. xi, fig. 3, VII. 



3 Ib., ib., pi. xii, fig. 10, vn. 



4 Tom. cit., p. 133, pi. vii, fig. 4. 



5 Marked h in fig. 2 of plate iii of the 1 Ossemens Fossiles,' torn, cit, and marked y in 'Anat, of 

 Vertebrates,' torn, cit., p. 157, fig. 98, c. 



6 Op. cit., p. 147. 



7 " On the Communications between the Tympanum and Palate in the Crocodilia" ut supra, pi. xl, 

 fig. 1, e. 



8 Ib., ib., v. 



