132 ON THE MOKPHOLOGICAL CONSTITUTION OF 



the maxillary resumes its connection with the pre-frontal, 

 which it had lost in the two other families on account of the 

 elongation of the snout. The pre-frontals in all the crocodilians 

 are separated from one another mesially by the passage back- 

 wards of narrow contiguous processes of the nasals, and by 

 similar processes which pass forwards from the so-called 

 "proper frontals" in this respect resembling the so-called 

 " nasals " of the bird, which are separated from one another 

 by the ascending processes of the intermaxillaries. 



Assuming the relations of the pre-frontals of the croco- 

 dilian to the maxillarj- arch as evidence of their being the 

 meta-neurapophyses of the ethinoidal sclerotome that is, 

 collectively, the homologue of the mammalian frontal the 

 next elements of this sclerotome to be determined are its 

 neurapophyses. At this point the type of ethmoidal sclero- 

 tome exhibited by the bird, and the modification of that type 

 presented by the chelonian, indicate its character in the 

 crocodilian. The descending processes of the pre-frontals of 

 the crocodiles are connected inferiorly to the ascending pro- 

 cesses of the so-called " palate-bones." Now, a bone connected 

 to the homologue of the mammalian frontal cannot well be 

 considered as the palate-bone, even although it be situated 

 between and united by suture to the maxillary and pterygoid. 

 But a bone with such relations, if viewed in the light of the 

 corresponding relations of the ethmoidal neurapophyses of the 

 bird, indicates its own real nature. The ethmoidal neura- 

 pophyses of the bird, connected above with the ethmoido- 

 frontals, form below more or less of the palatine vault. The 

 ethmoidal neurapophyses of the chelonians, pushed away 

 forwards and downwards from the ethmoido-frontal by the 

 ento-pterygoid, still form a part of the vault of the palate. (?) 

 In like manner I recognise, in the so-called " palate-bones " 

 of the crocodilian, the neurapophyses of its ethmoidal sclero- 

 tome. The ethmoido-frontals and neurapophyses of the bird, 



