984 W. K. GREGORY REPORT OF COMMITTEE ON NOMENCLATURE 



Palate, Prevoiner, Vomer, and Parasphenoid. — Vomer is by definition— 

 that is, occurrence in man— an unpaired membrane bone lying below the 

 basis cranii and stretching from the region of the pituitary to the region 

 of Jacobson^s cartilages. In r|;ian it arises as a pair of small elements 

 below the nasal septum^ with which a lot of other ossifications coalesce; 

 in most mammals — for example, Platypus, Perameles, Dasyurus, Talpa — 

 it arises by a single center under the posterior part of the nasal septum. 



The lizard vomer and those of Crocodiles, Sphenodon, Frogs, Urodeles, 

 and Camellia, arise as a pair of membrane bones surrounding the lower 

 and mesial sui'faces of the paraseptal cartilages, or what appear to be 

 their homologues in the Amphibia. The single vomer of Chelonia arises 

 from a pair of splints associated in the normal reptilii n way with the 

 paraseptals ; it is hence different in origin to the vomer of mammals. 



The parasphenoid of Sphenodon, Crocodilas, Urodeles, and Frogs is a 

 membrane element arising in the ventral surface of the basis cranii in 

 the hypophysial region, and running forward from here sometimes as 

 far as the nasal region. In lizards this median splint fuses with a pair 

 of small membrane ossifications lying below the basipterygoid processes 

 and forming with them the A^idian foramina. 



It will be seen that the mode of origin of the mammalian vomer is 

 much more like that of the reptilian parasphenoid than that of the rep- 

 tilian vomer. 



Every one must admit that the classical view of the homologies of these 

 bones is open to grave doubts. Their discussion takes a large part of 

 recent paleontological and embryological literature, and to retain all three 

 terms can not possibly lead to any confusion and reminds every one that 

 the problem is still open. 



The vomers of tortoises and birds are, of course, prevomers. 



Supratemporal and hitertemporal. — With regard to the terms Supra- 

 temporal and Intertemporal I am quite willing to accept these on the 

 score of current usage. 



Dermosup'aoccipital is a mouthful. Is it quite certain that MialFs 

 bones in the Crocodile are really the right thing, and not perhaps scutes 

 fused in?^ I have never been able to see them, and can not at the mo- 

 ment get at his description. In any case, could we not shorten it to Der- 

 moccipital, which is long enough ? 



However, if the rest of the committee are satisfied as to the identity of 

 the bones I will gladly accept it, particularly as MialFs book on the Croco- 

 dile is an excellent one. 



« See Professor WiUiston's remarks below, p. 985. 



