394 Systematic Paleontology 



branched and simple; ultimate branches vary in numbers and closeness, 

 sometimes few and remote, and again crowded, contiguous, almost touch- 

 ing; towards the summit of the penultimate branches the ultimate ones 

 become much crowded and grow gradually shorter, are cylindrical, 

 and taper gradually to an obtuse point; leaf -sears of young leaves ellipti- 

 cal in shape, slightly prolonged in the direction of the axes of the stems, 

 and such leaves seem to have been fleshy, slightly convex, and with a 

 free tip slightly keeled in the upper half; with age the leaves become 

 broader and more convex, being broadly elliptical, almost circular, and 

 they leave similar scars after their fall; when crowded and dilated with 

 age the leaves and leaf-scars are subrhombic or rhombic in shape; the 

 surface of the leaves, which is very rarely preserved, shows fine tubercles 

 or dots arranged in curving lines parallel to their margins and converg- 

 ing towards their tips; cones small, globular, or subelliptical in shape, 

 attached laterally to the penultimate twigs, taking the place of ultimate 

 branches; scales numerous, spirally arranged, touching, shape not made 

 out, but probably with age rhombic and polygonal." — Fontaine, 1890. 



This species is fairly common in Virginia in beds of both Patuxent 

 and Patapsco age while in Maryland it occurs exclusively, as far as 

 known, in deposits referred to the Patapsco formation. 



All forms in this genus are much alike superficially as may be seen 

 by comparing the figure reproduced on pi. Ixiv of B. mammillare 

 Brongniart, the type species from the European Lower Oolite, with the 

 Potomac species, and these with the latest known American form, the 

 widespread B. macro car pum Newberry, which ranges from Greenland 

 to Delaware, Alabama and Kansas and Wyoming and from the Earitan 

 through the Magothy and Dakota to the Montana formation. 



B. crassicQAile is very similar to the European B. ohesum Heer ^ with 

 which Seward '' unites it tentatively. This latter species is found in the 

 English Wealden and in the Urgonian and Aptian of Portugal. One 

 of Saporta's figures of this species is reproduced on pi. Ixv, fig. 3, and it 

 will be seen thai; the European and American forms are very similar; 



^ Heer, Contrib. Fl. Foss., Port, 1881, p. 20, pi. 17, figs. 1-4. 



== Seward, Wealden FL, pt. ii, 1895, p. 218, pi. xvii, fig. 9; pi. xx, figs. 1, 2, 4. 



