THE ERIAN OR DEVONIAN FORESTS. 



85 



in Ohio by Prof. Edward Orton, and at Chicago by Dr. H. A. John- 

 son and Mr. B. W. Thomas, also in New York by Prof. J. M. Clarke. 



The macrospores collected by Mr. Thomas from the Chicago 

 clays and shales conform closely to those of Kettle Point, and prob- 

 ably belong to the same species. Some of them are thicker in the 

 outer wall, and show the pores much more distinctly. These have 

 been called by Mr. Thomas S. Chicagoensis, and may be regarded as 

 a varietal form. Specimens isolated from the shale and mounted 

 dry, show what seems to have been the hilum or scar of attachment 

 better than those in balsam. 



Sections of the Kettle Point shale show, in addition to the ma- 

 crospores, wider and thinner shreds of vegetable matter, which I am 

 inclined to suppose to be remains of the sporocarps. 



2. Protosalvinia ( Sporangites) Braziliensis, Dawson, " Canadian 

 Record of Science," 1883. — Macrospores, round, smooth, a little 

 longer than those of the last species, or about one seventy-fifth of 

 an inch in diameter, enclosed in round, oval, or slightly reniform 

 sporocarps, each containing from four to twenty-four macrospores. 

 Longest diameter of sporocarps three to six millimetres. Structure 

 of wall of sporocarps hexagonal cellular. Some sporocarps show no 

 macrospores, and may possibly contain microspores. The specimens 

 are from the Erian of Brazil. Discovered by Mr. Orville Derby. 

 The formation, according to Mr. Derby, consists of black shales be- 

 low, about three hundred feet thick, and containing the fucoid known 

 as Spirophyton, and probably decomposed vegetable matter. Above 

 this is chocolate and reddish shale, in which the well-preserved speci- 

 mens of Protosalvinia occur. These beds are very widely distributed, 

 and abound in Protosalvinia and Spirophyton, 



3. Protosalvinia (Sporangites) bilobata, Dawson, "Canadian 

 Record of Science," 1883. — Sporocarps, oval or reniform, three 

 to six millimetres in diameter, each showing two rounded 

 prominences at the ends, with a depression in the middle, and 

 sometimes a raised neck or isthmus at one side connecting the 

 prominences. Structure of sporocarp cellular. Some of the speci- 

 mens indicate that each prominence or tubercle contained several 

 macrospores. At first sight it would be easy to mistake these bodies 

 for valves of BeyricJiia, 



Found in the same formations with the last species, though, in so 

 far as the specimens indicate, not precisely in the same beds. Col- 

 lected by Mr. Derby. 



4. Protosalvinia Clarkei, Dawson, P. bilobata, Clarke, " American 

 Journal of Science." — Macrospores two-thirds to one millimetre in 



