146 Mr. F. M'Coy on the Fossil Botany and Zoology 



of fossil plants from the supposed oolitic coal-field of Burdwan, 

 but without any description or definition. Similar bodies are not 

 uncommon in the shales and clays of the Australian coal-fields ; 

 but although the genus is noticed by Unger in his l Conspectus 

 Florae Primordialis/ and Mr. Morris has noticed its occurrence 

 in this district, no botanist has as yet given any descriptive ac- 

 count either of the genus or species ; and so obscure are the rela- 

 tions to other forms, that doubts have even arisen as to what 

 part of the plant the radiated cylindrical fossils might be sup- 

 posed to represent, and how its parts should be named. A 

 distinguished botanist has suggested to me that the cylindrical 

 fossil might be considered a stem, the axis being the pith, the 

 radiating divisional lines the medullary rays, and the intervening 

 cuneiform masses the wedges of wood. I have carefully consi- 

 dered this opinion, but find it impossible to adopt it, from the 

 ease with which the transverse fractures take place, and the per- 

 fection of the surfaces produced, as it is obvious that such nume- 

 rous and perfect divisional planes, as we observe at right angles 

 to the axis, would be incompatible with the above view. On the 

 whole, after a careful study of the specimens at my disposal, I feel 

 disposed to view the genus as closely allied to Sphenophyllum, in 

 which we have a jointed stem surrounded by verticillate whorls of 

 from six to twelve wedge-shaped leaves with dichotomous veins ; 

 and in this light Vertebraria becomes intelligible, for I have 

 clearly ascertained the existence of the dichotomous neuration 

 on each of the wedge-shaped divisions of the transverse planes, 

 which will, according to this view, represent the surface of a 

 whorl of verticillate leaves, and we may consider therefore the 

 main difference between Spkenophyllum and Vertebraria to con- 

 sist in the greater approximation of the whorls of leaves in the 

 latter, the internodes being so very short that the whorls of leaves 

 are brought in contact, or nearly so. I might therefore provi- 

 sionally characterize the genus as follows : — 



Gen. Char. Stem slender, surrounded by densely aggregated 

 whorls of verticillate, cuneiform leaves, having a dichotomous 

 neuration. 



To the above we might add, that the number of leaves in a 

 whorl depends on the species, and that from the whorls being so 

 close as nearly to touch each other, the fossils have the appear- 

 ance of lengthened cylinders, breaking readily in a horizontal and 

 vertical direction — the former coinciding with the surfaces of the 

 leaves, the latter coinciding with the vertical prolongations of the 

 lines separating the leaves of each whorl — the former producible 

 in indefinite number at distances of about a line from each 

 other, the latter having only a small definite number depending 



