560 Trof. E. W. Claypole — Fossil Tree from the U. Silurian. 



areoles. Lower portion of each areola depressed and probably 

 representing, or containing, a leaf-scar. Depressed portion of 

 areole (leaf-scar?) symmetrical {i.e. alike on right and left sides). 

 Vascular scars, leaves, fruit, etc., unknown. Ety. fyXu^w, I engrave; 

 from the depressed areoles. 



I append the following specific description : — 



Gltptodendron Eatonense. Stem thick and trunk-like, the 

 specimen described measured, when complete, about six inches in 

 diameter. Surface divided into rhomboidal areoles by two sets of 

 narrow ridges, parallel and equidistant, running spirally up the 

 stem in opposite directions. These ridges cross each other nearly 

 at right angles. The areoles thus formed measure about seven- 

 sixteenths of an inch along each diagonal. Lower portion of 

 areole deeply and evenly depressed, and probably representing 

 a sunken leaf-scar. Upper border of depressed portion rounded in 

 outline, and elevated, equalling in height the spiral ridges. Ety. 

 Eaton, Preble Co., Ohio, near which town the specimen was found. 



The only species of Lepidodendron and of Sigillaria yet described 

 from American rocks older than the Carboniferous are the following 

 in order of time : — 



Lepidodendron (Sigillaria) Vanuxemi, Gceppert, 1836; "Flora Silurisch.'' Chemung 



Group, New York. Figured in " Geology of 3rd District of New York," 



p. 184; also in Dana's "Manual," 1874, p. 277. 

 Sigillaria simplicitas, Vanuxem, 1842 ; " Geology of 3rd District of New York," 



p. 190. Catskill Group. 

 Lepidodendron (Siqillaria) CJmnungense, Hall, 1843; "Geology of 4tli District," 



p. 275. Chemung Group. 

 Lepidodendro7t 2^rin>cevum, Eogers, 1858; "Geology of Pennsylvania," p. 828. 



Hamilton Group. 

 Lepidodendron Gaspianum, Dawson, Quart. Journ. Geol. Soc. 1859, vol. xv. p. 483, 



Catskill Group. See also "Acadian Geology," 1868, p. 542 ; Eogers's 



" Geology of Pennsylvania," p. 829, fig. 677 ; " Geology of 3rd Disti-ict of 



New York," p. 157. 

 Sigillaria palpebra, Ba-wson, 1862; Quart. Journ. Geol. Soc. vol. xviii. p. 309. 



Hamilton Group. 

 Lepidodendron corrugatum, Dawson, 1860; Quart. Journ. Geol. Soc. vol. xv. p. 68; 



from Akron, Ohio, formerly referred to the Devonian, is now regarded as of 



Lower Carhoniferous age; Dawson's "Eeport on Fossil Plants of Canada," 



1871, p. 34. 

 The following table will show the relation of this new fossil to 

 those of the two genera, named above, previously known in 

 America: — (see table on next page). 



In 1861 Dr. Dawson mentioned the occurrence of PsilopJiyton 

 princeps in the Gaspe Limestone of Lower Helderberg (Ludlow) 

 age in Canada ; but, from that time, the writer is not aware of the 

 annoimcement of any discovery of like nature until 1877, when 

 Dr. Carl Eoeninger, State-Geologist of Michigan, discovered some 

 specimens of land-plants in the Lower Helderberg Limestone of 

 Monroe County in that State. These specimens were sent for 

 determination to Mr. Leo Lesquereux, of Columbus, Ohio, who has 

 described them to the American Philosophical Society at Phila- 

 delphia as Psilophytum cormitum, Lesq., and Annulana Boeningeri, 

 Lesq. With these exceptions, no indisputable traces of land plants 



