ABSTRACTS OF PAPERS 135 



anatomical evidence does not prove tlieir Araucarian ajfluities. Worlj; carried 

 out under tlie autlior's supervision makes it clear that true remains of the 

 genus Sequoia do not make their appearance till the upper members of the 

 Laramie series are reached. It will be necessary in the future to distinguish 

 between the true Sequoias of the later Laramie and of the Tertiary and those 

 Araucarian forms masquerading as Sequoias in the earlier Cretaceous and the 

 Jurassic. 



GENUS ARAUCARIOXYLON IN THE AMERICAN CRETACEOUS 

 _^ ^ BY E. C. JEFFREY 



{ Ah s tract) 



The author and his students have collected material of Araucarioxylon from 

 numerous localities and geological horizons of the North American Cretaceous, 

 which supply reasons for moditications in our views as to the origin of the 

 genus. It is generally assumed that the genus Araucarioxylon definitely con- 

 nects the Araucarian conifers of the present epoch with the Cordiatales of the 

 Paleozoic. The structure of woods in the American Cretaceous lends little 

 support to that opinion, since they are less like the wood of Gordaites than 

 are the woods of Aruticuria and Agathis. The woods of the Araucarioxylon 

 type in our deposits have the organization of Cupressinoxyla and the earlier 

 annual rings of stems lack the Araucarioxylou-pitting. It is assumed from 

 these data that the living Araucarian conifers are not closely related to the 

 Cordaitales, but rather to a complex from which the Abietinene or Pine family 

 has taken origin. The roots of the living genera of the Araucarinese are or- 

 ganized largely as is the stem of their Cretaceous ancestors. 



CUPRESSINOXYLA OF THE ME80Z0IC 

 BY E. C. JEFFREY 



{Abstract) 



The genus Cupressinoxylon, established many years ago, is of wide occur- 

 rence in the Jurassic and Cretaceous. It is generally assumed that woods of 

 this type are to be referred to the Cupressinese, Taxodinese, or Podocarpinese. 

 The intention of the present communication is to show that many such woods 

 are of Araucarian affinities. In a number of instances Araucarian pitting can 

 be observed in such woods, while in others more refined criteria of Araucarian 

 affinities have to be employed. Evidence is supplied on the one hand of the 

 character of the ancestors of these Araucarian Cupressinoxyla and proof is 

 furnished on the other of their being the ancestral types from which the living 

 Araucariinese have been derived. The genus Cupressinoxylon is formed as a 

 response to marked seasonal variations of temperature and evidence is fur- 

 nished for this conclusion. , 



An instructive presentation, illustrated by lantern slides and speci- 

 mens^ of a new reptilian suborder followed : 



