1870.] DAWSON— SPORE-CASES IN COAL. 371 



viewed as transparent objects, appear yellow like amber, and show 

 little structure, except that the walls can, in some cases, be dis- 

 tinguished from the internal cavity, and the latter may be seen to 

 inclose patches of floccuient or granular matter. In the shale 

 containing them there are also vast numbers of rounded translu- 

 cent granules which may be the escaped spores. 



The bed at Kettle Point is stated in the report of the Geologi- 

 cal Survey to be 12 to 14 feet in thickness ; but to what degree 

 either in its thickness or horizontal extent it retains the charac- 

 ters above described, I do not know. It belongs to the Upper 

 Devonian, being supposed to be a representative of the Gennessee 

 slates of New York. It contains stems of Calamites inornatiis 

 and of a Lfpulodeiidron, obscurely preserved, but apparently of 

 the type of L. Veltheiniianum, and possibly the same with L. 

 primceoum of Rogers. The spore cases are not improbably those 

 of this plant, or of the species L. G.ispianum, which belongs to 

 the same horizon, though not found at this locality. The occur- 

 rence of this bed is a remarkable evidence of the abundance of 

 LycopodiacGOus trees, whose spores must have drifted in immense 

 quantities in the wands, to form such a bed. It is to be observed, 

 however, that this is not a bed of coal, but a bituminous shale of 

 brown color, and with pale streak, no doubt accumulated in water, 

 and even marine, since it contains Spiroplu/ton^ and shells of 

 Lingula. In this it agrees with the Australian Tasmanite, which 

 though composed in great part of spore-cases of Ferns, is, as I am 

 informed by IMr, Selwyn, an aqueous deposit, containing marine 

 shells. 



There is, however, one bed of true coal known in the Devonian 

 of Eastern America, that of Tar Point, Gaspe, and it is curious 

 to observe that this is not composed of spore-cases, but of succes- 

 sive thin layers of rhizomata and stems of Psilophf/ton, with 

 occasional fragments of Lepldodendron and Cij do stigma. Round- 

 ed disks which may be spore-cases, occur in it, but very rarely. 

 In the bituminous shales associated with this coal, the microscope 

 shows amber-colored flakes of irregular form, but these are easily 

 ascertained to be portions of the epidermis of Psilophyton, or of 

 the chitinous crusts of crustaceans which abound in these beds. 



Ascending to the Lower Carboniferous (sub-carboniferous), 

 there are great quantities c^ rounded spore-cases of the size of 



* The well known Cauda-gaUi fueoid. 



