Notes on" the Geology of Yates County, N. Y. 199 



The fossil remains are not plentiful, and can best be obtained in 

 quarries and cuttings. At Whitaker's quarry, in Milo, we have ob- 

 tained fine specimens of Orthoceras A treus, Hall, and 0. Thyestes, Hall. 

 Within the chamber of habitation of a large specimen of the latter, 

 which we collected at this locality, we found two perfect specimens 

 of Orthoceras, each about three inches long, and with chamber of habi- 

 tation one inch in diameter. The shell was broken off of one side in 

 getting out the specimen, thus exposing the interior. 



At a quarry in the town of Milo we obtained some specimens of 

 Lepidodendron which seem to be L. primcevum, Eogers, but pre- 

 sent the curious peculiarity of having the leaf-bases depressed, instead 

 of being prominent (see remarks on this by Dr. J. W. Dawson in the 

 Quarterly Journal of the Geological Society, May, 1881). In the same 

 quarry carbonized remains of immense fern petioles five inches broad 

 and several feet long occur. Fucoides grapliica, Hall, abounds in the 

 argillaceous strata, and a magnificent specimen of Spirophyton, sp. f 

 was found in the upper shales. Lunulicardium omatum, Hall, occurs 

 sparingly. " Cone-in-cone " and pyntiferous nodules of curious shapes 

 occur in the Big gully. Gardiopsis robusta, Hall, is met with quite 

 frequently. Mr. Wm. Buxton, of Milo Center, has found three fine 

 specimens of Plumalina plumaria, Hall, in the uppermost shales. One 

 of the specimens is fourteen inches long. We have never found Spi- 

 r if era Icevis. Hall, though ever on the look-out for it. 



At the Whitaker quarry, in the town of Milo, we discovered a fern 

 which Dr. Dawson has indicated as a new genus. The following is his 

 description taken from the Quarterly Journal of May, 1881 r 



Asteropteris koveboracensis. 



Plate XV —Figs. 6-15. 



" The genus Asteropteris is established for stems of ferns having the 

 axial portion composed of vertical radiating plates of scalariform tis- 

 sue imbedded in parenchyma, and having the outer cylinder composed 

 of elongated cells traversed by leaf-bundles of the type of those of 

 Zygopteris." 



" The only species known to me is represented by a stem 2 • 5 centi- 

 metres in diameter, slightly wrinkled and pitted externally, perhaps by 

 traces of aerial roots which have perished. The transverse section 

 shows in the center four vertical plates of scalariform or imperfectly 

 reticulated tissues, placed at right angles to each other, and united in 

 the middle of the stem (figs. 1-4). At a short distance from the 

 center each of these plates divides into two or three, so as to form an 

 axis of from ten to twelve radiating plates, with remains of cellular 

 tissue filling the angular interspaces (fig. 3, l). The greatest diameter 

 of this axis is about 1.5 centimetres. Exterior to the axis the stem 



