BULLETIN OF THE CEOLOCICAL SOCIETY OF AMERICA 



Vol. 24, pp. 241-246 June 9, 1913 



proceedings of the paleontological society 



HOMOLOGY OF THE "LACRIMAL" AND OF THE "ALISPHE- 

 NOID" IN RECENT AND FOSSIL REPTILES l 



BY WILLIAM K. GREGORY 



(Presented before the Paleontological Society December 30, 1912) 



CONTENTS 



Page 



Prefrontal, lacrimal, adlacrimal 241 



Alisphenoid and orbitosphenoid ... 24l> 



Pterygoid, epipterygoid, and alisphenoid 244 



Mutability of names in reptilian osteology 240 



Conclusions 246 



Prefrontal, Lacrimal, Adlacrimal 



In the skull of lizards there is a large triangular bone lying in the 

 anterior part of the orbit, above and behind the maxillary and below the 

 frontal. This bone, or pair of bones on opposite sides, is commonly called 

 the prefrontal. This prefrontal of lizards has been shown by Gaupp 2 to 

 resemble the lacrimal of mammals — that is, it has similar relations to the 

 surrounding bones, to the lacrimal duct, and to the underlying cartilage 

 skull in the embryo. On account of these resemblance's between reptilian 

 prefrontal and mammalian lacrimal, Gaupp believes thai these, elements 

 are homologous with each other, and hence he lias given up the name pre- 

 frontal for the reptilian clement and calls it instead lacrimal, in order to 

 make the terminjology of the reptilian skull conform with that of the 

 mammal. 



What, then, is that other bone of the Lizard skull which until Gaupp's 

 time has generally been called lacrimal? This is a small or vestigial 

 element lying below the large triangular bone and above the alveolar 

 border of the maxillar. Gaupp thinks thai this vestigial element has no 

 right to the name lacrimal, no matter how long it has borne thai name, 

 and hence he calls it adlacrimal, while Jaekel calls it postnasal. 



'Manuscript received bj the Secretary of the Paleontological Societj January 11, I9i:i. 

 11 has Lacrlmale des Menschen und der Sanger und seine morphologische Bedeutung. 

 Anal An/. Bd. 36, 1010, pp. 520-555. 



(241) 



