Dr. J. W. Dawson on Spore-cases in Coals. 323 



for tliese bodies the name of Sporangites huronensis. When 

 slices of the rock are made, its substance is seen to be filled with 

 these bodies, which, viewed as transparent objects, appear 

 yellow like amber, and show little structure, except that the 

 walls can in some cases be distinguished from the internal 

 cavity, and the latter may be seen to enclose patches of floc- 

 culent or granular matter. In the shale containing them there 

 are also vast numbers of rounded translucent granules, which 

 may be the escaped spores. 



The bed at Kettle Point is stated in the Report of the Geolo- 

 gical Survey to be from 12 to 14 feet in thickness; but to what 

 degree either in its thickness or horizontal extent it retains 

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

 the Upper Devonian, being supposed to be a representative 

 of the Gennesee slates of New York. It contains stems of 

 Calamites inornatus and of a Lepidodendron^ obscurely pre- 

 served, but apparently of the type of L. VeltJicimianumj and 

 possibly the same with L. primawum of Rogers. The spore- 

 cases are not improbably those of this plant, or of the species 

 L. gaspianum, which belongs to the same horizon, though 

 not found at this locality. The occurrence of this bed is a 

 remarkable evidence of the abundance of Lycopodiaceous trees, 

 whose spores must have drifted in immense quantities in the 

 winds, 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 

 colour, and with pale streak, no doubt accumulated in water, 

 and even marine, since it contains Sjjirojjhyton^ and shells of 

 Lvngida. 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 Mr. Selwyn, an aqueous deposit, con- 

 taining marine shells. 



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

 nian of Eastern America, that of Tar Point, Gaspe ; and it is 

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

 of successive thin layers of rliizomata and stems oi. PsilopTiyton^ 

 with occasional fragments of Lepidodendron and Cyclostigma. 

 Rounded disks, which may be spore-cases, occur in it, but 

 very rarely. In the bituminous shales associated with this 

 coal the microscope shows amber-coloured flakes of irregular 

 form ; but these are easily ascertained to be portions of the 

 epidermis of Psilopliyton^ or of the chitinous crusts of crusta- 

 ceans which abound in these beds. 



Ascending to the Lower Carboniferous (sub-Carboniferous), 

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



* The well-knowTi Cauda-nulli fucoid. 



