J. W. Dawson on Paleozoic Rhizocarps. 21 



mentioned that he had found similar bodies in the Hamilton 

 shales of New York, and that fchey were associated with the 

 curious pinnately leaved plant, Ptilophyion Vanuxemi, an 

 observation to which I subsequently referred in discussing the 

 affinities of this plant, in a report to the Geological Survey on the 

 Erian plants of Canada, published in 1882.* Prof. Williams 

 was kind enough to send me specimens, in which, however, the 

 round spore-case like bodies were much less distinct than in the 

 specimens from Ohio and Lake Huron. In the report above 

 referred to I have also noticed the occurrence of rounded spore- 

 like bodies in association with the stems of Trochophylhim of Les- 

 quereux from the Lower Carboniferous of Pennsylvania, and of 

 which specimens were submitted to me by Mr. Lacoe of Pittston, 

 and Prof. Lesquereux. TrochophyUmn I regard as closely allied 

 to or perhaps congeneric with Ptilophyton, and in the report 

 already referred to have argued that these plants were probably 

 aquatic. 



Still more recently Prof. J. M. Clarke, of Northampton, Mas- 

 sachusetts, was so kind as to send me two fragments of rock con- 

 taining Sporangites similar to those above mentioned — one from 

 the G-enessee shale of Canandaigua, N.Y., and another from the 

 Corniferous limestone. In the latter these bodies retain their 

 globular form, though some are partially crushed in such a way 

 as to show their membranous character. In slices prepared by Prof. 

 Clarke the wall is seen to be thin and carbonaceous, with indica- 

 tions of a dense cellular structure, and some of the specimens 

 show a projecting aperture or point of attachment at one side, 

 giving them a somewhat pear-shaped appearance. The size of 

 all these macrospores from the Erian of iNew York is nearly the 

 same with that of Lake Huron specimens. Those found with 

 Trochophyllum in the Lower Carboniferous are much larger. 



No certain clue seemed to be afforded by all these observa- 

 tions as to the precise affinities of these widely-distributed bodies ; 

 but in March last Mr. Orville Derby, of the Geological Survey 

 of Brazil sent me specimens found along with fronds of Spirophy- 

 ton in the Erian of that country, which seemed to throw a new light 

 on the whole subject. Mr. Derby's specimens recalled to remem- 

 brance certain fossils which had been sent to me several years 



* Report on Erian Plants of Canada. Part II. 



