554 PROCEEDINGS OF THE AMERICAN ACADEMY. 



cariopitys amcricana ^^ showing a series of traumatic resin canals. The 

 row nearer the center of the stem is larger and better developed, while 

 that farther out is composed of very small canals separated by wider 

 intervals. As has been pointed out in the article cited above, the 

 traumatic resin canals in Araucariopitys are more nearly like those 

 of the x\bietineae, than is the case with canals of this type which have 

 been described in any other American wood of Araucarian affinities. 

 In Araucariopitys the rays too are distinctly of the Abietineous type, 

 being composed of thick-walled cells, strongly pitted. The radial 

 bordered pits of the tracheids however are often arranged in the com- 

 pressed and sometimes in the alternating manner of the Araucarian 

 conifers. Moreover there are no bars of Sanio present, although 

 much of the material on which the genus Araucariopitys has been 

 founded is in a perfect condition of preservation. Gothan, as has 

 been indicated in the earlier paragraphs of this article, has described 

 woods of a similar type from the Jurassic beds of King Carl's Land 

 and Spitzbergen. These have traumatic resin-canals, thick-walled 

 and strongly pitted ray cells. This author does not figure the presence 

 of bars of Sanio in these woods of the arctic regions, so that it may be 

 assumed that they are absent as in Araucariopitj^s, especially as woods 

 of a similar horizon and identical features of organization, which I 

 have examined, show no indication whatever of these peculiar struc- 

 tures, which constitute transverse bands between the radial pits of 

 the tracheids, in all coniferous except Araucarian woods. Miss 

 Gerry has investigated the distribution of bars of Sanio in the Coni- 

 ferales in a comprehensive manner and found theni to be absent in all 

 Araucarian woods, living or extinct, which she examined.^ ^ Before 

 discussing the conditions found in the Araucariopitys type, it will be 

 well to consider briefly woods of a similar type from older geological 

 horizons. It is pertinent before doing this, however, to point out that 

 the Araucariopitys type, so far as our present knowledge goes, is 

 rare in the later Mesozoic (i. e., the Cretaceous). 



Figure d, Plate 7, shows the presence of two rows of resin canals of 

 the traumatic type in an Araucarian wood from the Upper Jurassic. 

 This wood and others of the same type will be described in detail on 

 another occasion. At the present time only those features, which are 

 of importance in the present connection, will be dealt with. The 

 section from which Figure d, Plate 7, was made, shows a distinct wound 

 cap a few annual rings away from the pith. From this on either side 



35 .Jeffrey, Bot. Gazette, 44, pps. 435-444. 



36 Distribution of Bars of Sanio in the Coniferales, Ann. Bot. 24, pp. 119-124. 



