232 MESOZOIC FLORAS OF UNITED STATES. 



the Catalogue of the United States National Museum, and Fig. 27 that 

 numbered 3997, both of which were formerly referred to Aspidiuni 

 heterophyllwn. Figs. 28 and 29 show, respectively, the specimens 

 originally referred with doubt to Pecopteris strictinervis and Osmunda 

 dicksonioides. 



These fossils occur at localities Nos. 9, 18, 19, 20, and 22. 



Most of the fossils occur at the localities Nos. 9 and 22, being most 

 numerous at No. 9. 



Gleichenia ? Gilbert-Thompsoni Fontaine n. sp." 

 PI. LXVI, Fig. 11. 



The plant here regarded as a new species was found by Mr. Gilbert 

 Thompson in the Shasta formation of the Lower Cretaceous of California. 

 The locality is Pettyjohn's ranch, 12 miles west of Red Bluff, Tehama 

 County, Cal. It was long ago submitted to Leo Lesquereux and by 

 him determined as a Pecopteris, but without fixation of the species. 

 The specific name here assigned to it is derived from its discoverer. 



The plant, although in a fragmentary condition, is Avell preserved 

 in the parts obtained and very distinct. It is of a well-marked char- 

 acter or facies, which is not very common in a formation so late as the 

 Shasta formation, but which is more characteristic of the Carboniferous 

 formation. It is not unlike Pecopteris arhorescens (Schloth.) Brongn. 

 of that formation. It is obviously a new species. The fossil is preserved 

 in a fine-grained gray sandstone, which does not show any of the nerves 

 of the pinnules except the midnerves. A portion of the penultimate 

 rachis is preserved and to this are attached a number of ultimate pinnae. 

 The penultimate rachis is strong, straight, and rigid. The ultimate 

 pinnae have none of their tips preserved. Thej^ are linear and pecu- 

 liarly rigid in aspect and must have had strong rachises and been quite 

 long. Some of those that are preserved show a length of 6 cm., with 

 no diminution in the size of the pinnules. The pinnules are closelj^ 

 crowded, oblong in form, attached by the entire base and have very 

 obtuse tips. From the base to the end of the pinnule the same width 

 is maintained, so that the margins are parallel. The texture of the 

 pinnules seems to have been thick and coriaceous. In each pinnule 



« See pp. 217-218. 



