536 BRITISH FOSSIL REPTILES. 



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

 (y, y) in Hi/lceochampsa and the concomitant recession of the maxillaries (21) from the 

 outer boundaries of the openings («, «, PI. 60, 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."^ 



But although it may be admitted that the pair of medial openings (fig. 25, *, «) answer 

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

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

 contended that the small sin2;le 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, «) placed at the hind surface 

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

 not with the vascular foramen,' in Crocodilm. 



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

 Crocodiles is divided by a pterygoid partition ; although Cuvier makes the absence of 

 this division, or inconspicuousness of the septum, a character of the skull of procoelian 

 Gavials.* Hi/laochampsa may show this partition in an exaggerated degree, and the 

 orifices s, s, and not the orifice e, would be the hinder nostril. 



Whatever alternative may commend itself to competent Palaeontologists, the palatal 

 characters which distinguish Hi/Iaochampsa from all other known Reptiles, recent or fossil, 

 are unaffected. 



I have had no opportunity of studying the palatal characters in GoniophoHs, 

 Suchosaurus, or any other Wealden Crocodile than the subject of the present Monograph. 



1 Op. cit., p. 147. 



• " On the Communications between the Tympanum and Palate in the Crocodilia" ut siqjra, pi. xl, 

 fig. 1, e. 



3 lb., ib., V. 



* " La cloisou qui diviseles uarines ne se montre pas a leur ouverture posterieure." ' Oss. Foss,,' torn, 

 cit., p. 106. 



