122 MESOZOIC FLORAS OF UNITED STATES. 



1874. Ginkgo digitata (Brongn.) Heer: Kegel's Gartenflora, Jahgr. XXIII, p. 261, 



pi. dcccvii, figs. 1-4. 

 1874. Ginkgo integriuscula Heer: Kegel's Gartenflora, Jahrg. XXIII, p. 261, pi. 



dcccvii, fig. 5. 

 1876. Ginltgo digitata (Brongn.) Heer: Fl. Foss. Arct., Vol. IV, Pt. I (Beitr. z. Foss. 



FI. Spitzbergens) , p. 40, pi. x, figs. 1, 5a b, 6. 

 1876. GinJcgo digitata hiloha Heer: Op. cit., p. 41, pi. viii, figs, la, laa. 

 1876. Ginkgo digitata quadriloha Heer: Op. cit., p. 42, pi. x, figs. 3a, b. 

 1876. Ginkgo digitata multiloia Heer: Op. cit., p. 42, pi. x, fig. 2. 

 1876. Ginkgo digitata angustiloia Heer: Op. cit., p. 43, pi. x, fig. 4. 

 1876. Ginkgo integriuscula Heer: Op. cit., p. 44, pi. x, figs. 7-9. 

 1878. Salisburia digitata (Brongn.) Sap.: Plantes Jurassiques, Vol. Ill, p. 294, pi. clx 



[xxxii], figs. 1-5. 

 1881. Ginkgo digitata integriuscula (Heer) Kollbrunner: Jahresb. d. Ostscliweiz- 



Geogr.-Comm. Ges. in St. Gallen, 1880-1881, pp. 62, 77." 



I will place with this species those leaves that have the following 

 character, ignoring possible sporadic variation: 



Leaf substance thin; leaves small, with a wide spread, being wider 

 than long ; segments numerous and not deeply incised, wide in proportion 

 to their length, closely placed and widest near or at their ends, so that 

 they have an obcuneate form; ends obtusely rounded, truncate, or 

 slightly notched. 



This type is represented in the Oregon Jurassic by a considerable 

 number of specimens, but not by so many as some other types. They 

 vary somewhat in size, but are all small in comparison with the forms of 

 the lepida and Huttoni type. This type tends to pass into the sibirica 

 type more than into am^ other. 



PI. XXX, Fig. I, gives a nearly entire medium-sized leaf, showing 

 a portion of its petiole. Two of the lobes of this are shown slightly 

 enlarged in Fig. 2. Fig. 3 shows a part of the summit of one of the leaves 

 having the most numerous segments. Fig. 4 represents a nearty entire 

 leaf of the largest size. This is shown slightly enlarged in Fig. 5. Figs. 

 6 and 7 give a part of a leaf having the widest segments seen. This 

 shows a portion of the petiole. 



The digitata type of Ginkgo is pretty widely distributed in the Oregon 

 Jurassic. It is found at localities Nos. 2, 7, 14, and 19. 



« This may have been simply an error of KoUbrunner's in failing to observe that Heer gave this form specific 

 rank. Bartholin in 1894 (Bot. Tidsk., Vol. XIX, pp. 96, 97, 108, pi. iv [xii], fig. 1), reduced it to a variety.— 

 L. F. W. 



