304 Systematic Paleontology 



Celastrophyllum proteoides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv. 



1889, p. 304, pi. cxivi, fig. 5. 

 Acacicephyllum microphyllnm Fontaine, 1906, in Ward, Mon. U. S. Geol. 



Surv., vol. xlviii, 1905, p. 486. 



Description. — ^' Frond bipinnate or tripinnate; rachises comparatively 

 stout; leaf -substance thick; pinnules varying in size and shape with 

 their position on the pinnse and frond; in shape they are ovate-elliptical 

 to subrhombic, the lower ones irregularly cut into oblong to elliptical 

 lobes ; the lower surface of the pinnules has a very iine granulation be- 

 tween the nerves, which can be seen distinctly only by the help of a lens ; 

 nerves closely placed, very fine but distinct on the under surface of the 

 pinnules, repeatedly branching and diverging flabellately.^' — Fontaine, 

 1890. 



This species is rare at all the localities where it has been collected and 

 is very poorly preserved. It includes the forms from the older Potomac 

 which Professor Fontaine considered of a dicotyledonous nature under 

 the name of Acaciccpliyllum, but which are obviously identical with the 

 type material of this species. A comparison of this author's pi. cxxxviii, 

 fig. 5, of Acacicephyllum with pi. clxix, fig. 1, of Thinnfeldia, will clearly 

 show this. The present writer has carefully compared all of the available 

 material, and there is not the slightest doubt but that the forms included 

 in the foregoing synonymy are all fragments of the same species. The 

 two specimens from the later Potomac at Federal Hill are retained and 

 included with the earlier forms of AcacicBphyllum referred to this species, 

 although they probably represent one of the Celastrophyllum species so 

 common at this locality. Their preservation is such that nothing definite 

 can be made out, and they are, therefore, queried as being doubtfully 

 determined. Forms from the ISTeocomian of Japan which resemble the 

 present species in a general way are described by Professor Yokoyama as 

 Glossozamites parvifolius and Adiantites lanceus, and similar forms 

 have been frequently referred to Adiantites. 



Occurrence. — Patuxent Formation. Dutch Gap, near Dutch Grap, 

 near Potomac Eun, Telegraph Station (Lorton), Virginia. Patapsco 

 Foemation. Federal Hill (?) (Baltimore), Maryland. 



Collection. — U. S. National Museum. 



