FLORA OF THE SHASTA FORMATION. 241 



shows them, seem somewhat different from those of the Potomac plants, 

 for they go off more nearly at a right angle from the midrib and are 

 mostly unbranched. 



The pinnules were evidently quite long and narrow, as is shown in 

 the specimen given in Fig. 5, which represents a fragment of the middle 

 portion of a pinnule. Fig. 6 gives the terminal portion of a pinnule, 

 which must have been larger than that represented by Fig. 5. Fig. 7 

 shows the lateral nervation. 



The undoubted specimens of this plant are not very numerous. They 

 occur at localities Nos. 9, 19, 20, and 22. The doubtful specimens are 

 numerous, and thej^ occur at localities Nos. 9, 14, 19, and 23. They are 

 mostly found at the last locality. 



Angiopteeidium strictinerve latifolium Fontaine. 

 PI. LXVI, Figs. 8-10. 



1889. Angiopteridiuin strictinerve latifolium Font.: Potomac Flora (Monogr. U. S. 



Geol. Surv., Vol. XV), p. 116, pi. xxx, figs. 1, 5. 

 1895 [1896]. Angiopteridium nervosum Font, in Stanton: Bull. U. S. Geol. Surv., 



No. 1.33, p. 22. (PI. LXVI, Figs. 9, 10.) 



A number of fragments of a fern were found that appears to be 

 Angiopteridium strictinerve latifolium Font., of the Lower Potomac of 

 Virginia. The largest and best preserved of these fragments is repre- 

 sented in PL LXVI, Fig. 8. This is a portion of a pinnule, probably 

 its middle part. It shows some of the midrib and of the lamina on one 

 side of the midrib. It must have been a pinnule at least 5 cm. wide. 

 There is no way to estimate its length, or indeed that of any of the 

 pinnules, since they are found only as small fragments. The midrib is 

 quite strong. The lateral nerves are also strong and have the character 

 shown in the Potomac plant. 



This form occurs at localities Nos. 16, 19, and 23, and near Riddles, 

 Oreg. A considerable number of fragments of pinnules are found at 

 No. 23, as well as fragments of pinnules of a smaller Angiopteridium, 

 which seems to be the typical A. strictinerve. 



This plant was formerly determined by me as A. nervosum, and it 

 is quoted as such by Dr. T. W. Stanton in Bulletin No. 133 of the United 

 States Geological Survey, page 22, but it proves, on further examination, 



MON XLVIII — 05 16 



