72 ROYAL SOCIETY OF CANADA 



ariau type, and approaches veiy near to tissues of Cordaltes on the one 

 hand and to that of Cycads on the other. 



Other doubtful species mentioned in the original account of Lepido- 

 phloios Acadianus (1865) above referred to, were those which I named Jj. 

 platystigma, L. tetragonus and L. prominulus. The first of these has 

 large rhombic leaf-scars like those of Lepidophloios placed on confluent 

 uneven leaf-bases, and with a central vascular scar which is double. These 

 characters do not correspond exactly with those of Lepidophloios, nor 

 with Sigillaria? like S. Menardii, Brongniart. - The second has perfectly 

 rhombic leaf-bases with a central leaf-scar strictly of Lepidodendroid 

 type, though sometimes appearing as a rounded spot without any distinct 

 vascular marks. The third is very near to this, but with more elevated 

 and rugose leaf-bases of smaller size ; but this ditference may be an acci- 

 dent of condition of growth and state of preservation. Some of my 

 botanical friends are inclined to refer all these to Sigillaria. but to this I 

 must demur, unless indeed that genus be regarded as place of refuge for 

 any Carboniferous tree which cannot be conveniently provided for else- 

 where, and indeed that has been to a large extent its use. 



This being the case, it may be appropriate here to inquire briefly as 

 to the normal characters of Sigillaria^, properly so-called. 



In regard to external form and markings, the typical Sigillarite are 

 treesjoften of great size, with the trunks covered with hexagonal or 

 shield-shaped leaf-scars, in each of which is seen a central vascular mark 

 with two elongated and often curved marks at either side. This indicates 

 a leaf with a very broad insertion, and usually long and rigid, and with 

 a midrib containing a vascular bundle and two lateral structures, cellular 

 or vascular, and of uncertain signiticauce. These leaf-scars are placed in 

 vertical rows on the middle of raised ribs which traverse the trunks 

 vertically and become narrower and more numerous toward the upper 

 part of the stem, and disappear by expansion of the bark toward the 



Sigillariie of this type have been cla.ssed with others having narrow 

 ribs no wider than the scars, to which the name Rhytidolepis has been 

 given, and these again pass into others in which the ribs disappear or 

 consist merely of rows of contiguous leaf-scai-s. To these the name of 

 Favularia has been given. 



It is obvious that these ap]jearances present some resemblance to 

 those of Lepidophloios^ but yet in the typical forms there are marked and 

 essential points of ditference in the vertical arrangement of the leaf-bases 

 and in the character of the vascular impressions, which imply differences 

 in internal structure and foliage. To these have to be added the fact 

 that^the stems of Sigillariai seem to have been either simple or with few 

 branches, and that, so far as known, their fructification was borne in 

 bands [placed transversely on the stems and showing numerous small 



