250 MESOZOIC FLOKAS OF UNITED STATES. 



DiooNiTES BucHiANUs ABiETiNus (Goppert) Ward n. comb/' 



PL LXVII, Figs. 1-.3. 



1846. PterophyUum ahetinum Gopp. in Dunker: 



Monogr. d. Norddeutsch. Wealdenbildung, p. 15, pi. vii, fig. 2. 

 1851. Dioonites abietinus (Gopp.) Miquel: Tijdschr. v. d. Wis-en Naturk. Wetensch. 



V. h. Kon.-Ned.Inst. Amsterdam, Deel IV, p. 212 [8]. 

 1889. Dioonites Buchianus angustifolius Font.: Potomac Flora (Monogr. U. S. Geol. 



Surv., Vol. XV), p. 185, pi. Ixvii, fig. 6; pi. Ixviii, fig.' 4; pi. Ixxi, fig. 2 

 1894. Dioonites BucTiianus angustifolius Font, in Diller & Stanton: Bull. Geol. Soc. 



Am., Vol. V, p. 450. 

 1894. Zamiophyllum BucManus angustifolia (Font.) Yok. : Jour. CoU. Sci. Imp. 



Univ. Japan, p. 224, pi. xxii, fig. 4; pi. xxv, fig. 5: pi. xxviu, figs. 8, 9. 



Detached fragments of leaflets similar to Dioonites BucManus 

 abietinus Font., a plant occurring in the Lower Potomac of Virginia, 

 were found sparingly at localities Nos. 1, 9, 17, 19, and 20. Like 

 the similarly detached fragments resembling leaflets of D. Buchianus, 

 these are of doubtful character. But at locality No. 5, in the base of 

 the Horsetown beds, undoubted specimens, 5 in number, were found 

 of this plant. It is to be noted that the undoubted specimens of both 

 forms of D. Buchianus occur in the lower portion of the Horsetown beds. 

 The specimens have the leaflets attached to the midrib, and they are 

 uniformly narrow, even when attached, as in PI. LXVII, Fig. 1, low 

 down on the midrib. 



One specimen of this plant was collected in Oregon. This specimen 

 is a fragment of a leaf that shows 7 cm. of its length, with several leaflets 

 on the left side of the midrib. The leaflets go off very obliquely and 

 onlj" their basal portions are preserved. They are 2 mm. wide, and the 

 nerves are not visible. This plant resembles the Potomac form depicted 

 in Monograph XV of the United States Geological Survey, pi. Ixvii, fig. 6. 

 It was collected by Mr. Will Q. Brown from a locality about one-fourth 

 of a mile above the town of Riddles in Oregon. It occurs in a fine-grained 



n Professor Fontaine in liis Potomac Flora, p. 185, identified the Virginia plant with the form from the 

 Wealden of north Germany, which Dunker submitted to Goppert and which the latter in a letter to Dunker 

 named PterophyUum ahieiinum. Miquel five years later referred it to Dioonites. Although Professor Fontaine 

 reduced it to a subspecies of Dioonites Buchianus (Ett. ) Born., still under the rules of nomenclature the original 

 name of Goppert can not on that account be taken from it , but must remain as the name of the subspecies. The 

 above combination must therefore be substituted for the name that Professor Fontaine gave it {Dioonites 

 Buchianus angustifolius. — L. F. W. 



