no. 1821. REVISION OF POTOMAC PLANTS— BERRY. 305 



Leafy branches and twigs very similar in appearance to those of 

 BfachypTiyUum in which, however, the leaves are less thick and more 

 free and pointed are often referred to the genus Echinostrobus which 

 was founded by Schimper in 1872 for four or five Jurassic species of 

 conifers, and it is to this Jurassic genus that Velenovsky refers two 

 species from the Cenomanian of Bohemia, 1 although these latter are 

 both practically identical with Bracliyphyllum macrocarpum New- 

 berry from the nearly homotaxial American horizons. 



The geological range of Bracliyphyllum like its geographical range 

 is very great. The earliest recorded occurrence is that of a very 

 doubtful species described by Feistmantel 2 from the Permo-Car- 

 boniferous of New South Wales (Newcastle beds) . The genus reap- 

 pears in the upper Triassic becoming prominent during the Jurassic 

 and Lower Cretaceous and dies out during the first half of the Upper 

 Cretaceous. 



Recently discovered structural material has enabled Ilollick and 

 Jeffrey 3 to settle in a measure the botanical affinity of at least one 

 species, Bracliyphyllum macrocarpum. The leaves are shown to be 

 attached by practically the whole ventral surface, only the margins 

 being free and these sometimes overlap. They refer this species to 

 the subfamily Araucarieae on the evidence of the branched leaf trace, 

 the mucilaginous contents of the resin canals, the Araucarioxylon 

 type of flattened and alternating bordered pits, the lateral pits of the 

 ray cells and the absence in the phloem of regularly alternating rows 

 of hard bast fibers. 



Bracliyphyllum is not a prominent type in the Potomac flora 

 although it is by no means as rare as it was thought to be some years 

 ago. BrachypJiyllum parceramosum, the Patuxent species, has been 

 met with rather infrequently, but BrachypJiyMum crassicaule is not 

 uncommon at a relatively large number of Patapsco outcrops. 



BRACHYPHYLLUM CRASSICAULE Fontaine. 



Brachyphyllum crassicaule Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, 

 p. 221, pi. 100, fig. 4; pi. 109, figs. 1-7; pi. 110, figs. 1-3; pi. Ill, figs. 6, 7; 

 pi. 112, figs. 6-8; pi. 168, fig. 9.— Fontaine, in Ward, Monogr. U. S. Geol. 

 Surv., vol. 48, 1906, pp. 529, 557, pi. 113, fig. 6. 



Description. — In 1890 Fontaine described this species as follows: 



Trees with large branches, irregularly pinnate; on the penultimate twigs the 

 ultimate branches lower and next to the main branch subdivide pinnately into 

 branches; those higher are unbranched and simple; ultimate branches vary in num- 

 bers and closeness, sometimes few and remote, and again crowded, contiguous, 

 almost touching toward the summit of the penultimate branches the ultimate ones 

 become much crowded and grow gradually shorter, are cylindrical, and taper grad- 



'Velenovsky, Gym bohm. Kreidef., 1885, p. 16, pi. 6, figs. 3, 6-8; Kvetena cesk<5ho cenomanu, 1889, 

 p. 9, pi. 1, figs. 11-19; pi. 2, figs. 1, 2. 



2 Feistmantel, Palaeont., Suppl. 3, 1878, p. 97, pi. 7, figs. 3-6; pi. 17. 

 3Hol!ick ar.d Jeffrey, Ainer. Nat., vol. 40, 1906, p 200. 



80796°— Proc.N .M. vol. 40—11 20 



