118 PROCEEDINGS OF THE PALEOXTOLOGICAL SOCIETY 



CERTA1X THEORETICAL CONSIDERATIONS AFFECTING PHYLOGENY AXD 



CORRELATION' 



BY W. D. MATTHEW 



(Abstract) 



The author emphasized the importance of the hybridism and admixture of 

 blood resulting from successive or continuous migration movements and pointed 

 out the resultant complexity of the phylum in any race of animals and the 

 effects upon its composition and progressiveness. of more or less remoteness 

 from the center of dispersal. 



The next paper, illustrated by lantern slides (10 minutes) and dis- 

 cussed by E. C. Case and W. D. Matthew, was entitled 



HOMOLOGY OF THE "ALISPHENOID" AXD -LACHRYMAL-' IN RECEXT AXD 

 FOSSIL VERTEBRATES 



BY W. K. GREGORY 



(Abstract) 



The author reviewed the recent studies of Gaupp upon the homologies of 

 these bones in mammals and reptiles, but dissented from his conclusions, 

 which were based chiefly upon comparisons" of the modern lizard skull with 

 that of mammals. The lizards are highly specialized and remote from mam- 

 malian affinities ; the Permian Therocephalia and Cynodonts. approaching 

 nearly the ancestry of mammals, afford a much better guide to the homologies 

 of the skull bones. The recent studies of Broom, and especially of Watson, on 

 the skull structure in Cynodonts afford data for homologizing the bones of 

 the skull with those of mammals. Whatever homologies were accepted, the 

 author protested against hasty and unnecessary changes in nomenclature of 

 the skull bones in different vertebrate groups. Homologous boues in different 

 classes of vertebrates may be totally different in function and relations, and 

 it is neither necessary nor desirable that the nomenclature ot such bones 

 should be identical. 



The next paper, illustrated by charts and specimens (10 minutes), was 



CUBAN FOSSIL MAMMALS; PRELIMIXARY XOTE 

 BY W. D. MATTHEW 



(Abstract) 



The extinct land vertebrate fauna of Cuba had been practically unknown 

 until the recent discoveries of Dr. Carlos de la Torre, of Havana, and Mr. 

 Barnum Brown, of the American Museum of Natural History. These collec- 

 tions, in addition to specimens secured by Senor Moreno, of Havana, are now 

 at the American Museum in course of preparation and study. A preliminary 

 review showed that the fauna consisted of a remarkable group of ground 

 sloths, a few rodents allied to the Hutias still living on the island: a gigantic 

 crocodile, a large land tortoise, and aquatic turtles, lizards, and snakes. Three 

 genera and six species of ground sloths are readily distinguished ; all are allied 



