DEVELOPMENT OF THE SKULL OF EMYS 761 



55. The praemaxillare is of small size, situated entirely ventral 

 to the olfactory capsule. 



56. The parietale and froiitale are wholly lateral in position 

 and do not begin at this stage to arch in the cranial cavity dor- 

 saUy. The parietale exhibits a large processus inferior which 

 extends downward, lateral to the pila prootica, to come at length 

 into close relation with the free end of the processus ascendens 

 palatoquadrati. A cavum epiptericum is hereby formed. 



57. The praefrontale . is exceedingly large and becomes very 

 thick at its anterior margin, dorsal to the olfactory capsule. 



58. The pterygoideum exhibits a pronounced crista ptery- 

 goidea on its dorsal side which separates the fossa supraptery- 

 goidea from the sulcus cavernosus. 



59. The palatinum and vomer complete the roof of the mouth 

 at the stage modelled although later a separate parasphenoideum 

 is present in the region of the fenestra hypoph\^seos. The vomer 

 is unpaired but is derived from a paired condition. 



60. In the lower jaw all the investing bones of the adult except 

 the complementare are present at the stage modelled. 



61. Along the lateral side of the dentale is the sulcus alveolaris 

 inferior which becomes converted into the canalis alveolaris 

 inferior of older embryos. 



62. The goniale in the stage modelled is penetrated by the 

 canalis gonialis in which the chorda tympani passes from the 

 posterior end of the goniale obliquely forward and laterally to 

 attain the canalis primordialis. 



BIBLIOGRAPHY 



No attempt is made in this bibliography to give a complete list of the works 

 on the morphology of the skull, as such a list is to be found in Gaupp, 1905 b, and 

 more specifically for the chelonian skull in Nick, 1912. Only the more recent and 

 important works which are referred to in the body of the paper are here mentioned. 



Bender, O. 1911 Ueber Herkunft und Entwickelung der Columella auris bei 



Testudo graeca. Anat. Anz., Bd. 40, pp. 161-177. 

 BojANUs, L. H. 1819 Anatome Testudinis Europaeae. Vilnac, 1819-1821. 

 FiLATOFF, D. 1906 Zur Frage liber die Anlage des Knorpelschadels bei einigen 



Wirbeltieren. Anat. Anz., Bd. 29, pp. 62.3-633. 



1907 Die Metamerie des Kopfes von Emys lutaria. Zur Frage liber 



korrelative Entwicklung. Morph. Jahrb., Bd. 37, pp. 289-396. 



