Report of the exploring expedition to the Rocky Mountains in the year 1842, and to Oregon and north California in the years 1843-44 . oaches somewhat thesphenopteris rigida, (Brong.,) but differs essentially jn the smaller pinnules,which are usually nearly opposite, and in never being more than sub-trilo-bate, while in S. rigida they are often deeply 5-lobed. 3. Sphenopteris (?) paucipolia PI. 2, figs. 1, I a, 1 b, 1 c, 1 d. ( of collection.) Description.—Frond tripinnate ; rachis rather slender, with long, lateral,straight branches, which are slightly oblique; pinnae slender, nearly at
Report of the exploring expedition to the Rocky Mountains in the year 1842, and to Oregon and north California in the years 1843-44 . oaches somewhat thesphenopteris rigida, (Brong.,) but differs essentially jn the smaller pinnules,which are usually nearly opposite, and in never being more than sub-trilo-bate, while in S. rigida they are often deeply 5-lobed. 3. Sphenopteris (?) paucipolia PI. 2, figs. 1, I a, 1 b, 1 c, 1 d. ( of collection.) Description.—Frond tripinnate ; rachis rather slender, with long, lateral,straight branches, which are slightly oblique; pinnae slender, nearly at rightangles, alternate and opposite ; pinnules minute, oval-ovate, somewhat dis-tant, opposite or alternate, expanded or attenuate at base, sometimes deeplybibbed or digitate; midrib not apparent. This species was evidently a beautiful fern of large size, with slender,sparse foliage, giving it a peculiarly delicate appearance. In some of itsvarieties, (as figure 1 b,) it resembles Sphenopteris digitata; Phillipss Geo!, FOS SIL TERNS tlON OF THE OEOVBAPmCAL SL OREGON AHD NORTH CALIFOKMA PI I OfTHS ^O^ SUM* OF. HA iy-E Weber ? - 305 [ 174 ] Yorkshire, p. 147, pi. 8, figs. 6 and 7; Sphen. Williamsoni, Brong. Foss., i, p. 177, t. 49, figs. 6, 7, and S. The fossil under consideration,however, is quite a different species. In the figure 1 a, the branches andpinnules are more lax; figure 1 d is a magnified portion. In its general aspect, this fossil resembles the genus Pachypteris, towhich I had been inclined to refer it, but for the digitate character of thepinnules manifested by some specimens. 4. SPHENOPTERIS (?) TKIFOLIATA, PI. 2, figS. 2, 2 tt. (No. 86 Oi Collection.) Description.—Frond bipinnate ; pinna? trifoliate ; pinnules elliptic, nar-rowing at the base; rachis slender, flexuous; fructification terminal,raceme-like, from the pinnules gradually becoming single and fructiferous. Fig. 2 a—part of the fructiferous portion enlarged, showing the
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Keywords: ., bookauthorunitedstatesarmycorps, bookcentury1800, bookdecade1840
