CEOCODILID^. 45 



riorly ; supratemporal fossae very small or obliterated ; premaxillary 

 fissure heart-shaped ; upper teeth equal to or less numerous than 

 lower, and the smaller lateral ones biting externally to them ; both 

 1st and 4th lower teeth received into pits in the cranium ; 3rd 

 lower tooth much smaller than 4th ; mandibular vacuity large. 

 Frequently a dermal ventral armour. 



Alligator, sp. 



The following spocimen probably belongs to one of the existing 

 Brazilian species like A. latirostris, A. multiscutatus, and A. piinc- 

 tatus. 



Hah. S. America (Brazil). 



18880. A caudal vertebra of a small individual; from a cave in 

 Minas Geraes, Brazil. 



Claussen Collection. Purchased, 1845. 



Genus DIPLOCYNODON, Pomel 1 . 

 Syn. Ortkosaurus, Geonroy 2 ; Pleurodon, Meyer 3 . 



The generic identity of the forms to which the three above- 

 mentioned names were applied is indicated by Meyer in the ' Neues 

 Jahrb.' 1857, p. 538. Pomel's name is adopted as being the one 

 first well defined. 



Cranium short and broad, with the palatal aspect of the pre- 

 maxillte short, and their posterior border straight ; upper teeth 

 more numerous than lower, and the smaller lateral ones biting 

 externally to them ; 1st lower tooth received into a pit, and 4th 

 (normally) into a notch in the cranium ; 3rd lower tooth nearly as 

 large as 4th; supratemporal fossa of medium size; premaxillary 

 fissure heart-shaped ; mandibular vacuity large. A dermal ventral 

 armour. 



Diplocynodon hantoniensis (Wood 4 ). 



Syn. Alligator hantoniensis, Wood 5 . 

 Crocodilus hastingsife, Owen 6 . 



1 Bull. Soc. Geol. France, ser. 2, vol. iv. p. 383 (1847). 



2 Eevue Eucyclopedique, vol. fix. p. 91 (1833). — Insufficiently described. 



3 Nr.ues Jahrb. 1839, p. 77 (errorim, Plcrodon). 



4 Charleswortk's London Geological Journal, pt. i. p. 6 (1846). — Alligator. 



5 Loc. cit. 6 Eep. Brit. Assoc, for 1847, Trans, of Sections, p. 66 (1848). 



