•"344 MR ROBERT KIDSTON ON 



pendicles to cones, and are covered with obovate scales, apparently different from those 

 occurring on the branches. 



The number of rows of tubercles on Halonia vary considerably. Four rows have 

 frequently been stated as the number, but on many examples the number is greater. 



Some authors refer to the scars on Halonia as being cup-shaped. On decorticated 

 specimens of Halonia I have never seen them assume this form — as far as my experience 

 goes, they are always in the form of tubercles, and any figures that I have seen with 

 cup-shaped scars, which have been referred to Halonia, have belonged to one or other of 

 the Ulodendroid Lycopods, never to Halonia. * 



Leaf-Cushion and Position of the Leaf-Cicatrice. 



Goldenberg figures (loc. cit.) two specimens of Lepidophloios laricinus from which the 

 position of the leaf-cicatrice can be discovered. That given on his pi. iii. fig. 14, shows 

 a bifurcation, and the leaf-cushion is seen to bear the leaf-scar at its lower extremity. 

 The two large scars on this stem — one on each fork — may indicate the position of branches 

 which have been broken off. The other figure given by Goldenberg, which shows the 

 natural position of the branch, is that on his pi. xvi. fig. 6, which clearly shows the leaf- 

 cicatrice at the lower end of the cushion, or what might perhaps be more correctly 

 described as the leaf-scar situated at the top of the downward directed cushion. This 

 specimen is a most interesting one, and seems to represent the Halonia condition of the 

 plant. 



In the figure of Lepidophloios Scoticus given by Dr MACFARLANE,t the leaf-cushion? 

 are also directed downwards. His specimen likewise shows the Halonia condition. I 

 shall have occasion presently to refer to the arrangement of the leaf-cushions on the cone 

 pedicels of this species, whose leaf-scar is situated at that end of the cushion which is 

 directed upwards towards the cone. 



Among other characters, Corda distinguished his genus Lomatophloios from Lepido- 

 phloios by the upward directed leaf-cushions, whose leaf-cicatrice is situated at the upper 

 extremity. We shall also find that this position of the leaf-scar is found on Lepidopldoios 

 acerosus L. and H., sp., with which Corda's Lomatophloios crassicaule appears to me 

 to be identical. 



The direction of growth of the leaf-cushion I cannot accept as of generic importance, 

 especially as it will be shown presently that the direction of the leaf-cushion differs on 

 the younger and older branches of Lepidopldoios Scoticus. 



In Goldenberg's figure, however,^ the smaller branches which spring from the main 

 stem of Lepidopldoios laricinus have the leaf-cushions and cicatrices placed in the same 

 position as that which they are found to occupy on the main stem. 



* Halonia disticha, Morris, Trans. Geol. Soc, 2nd ser., vol. v. pi. xxxviii. fig. 1, is Sigillaria discophora. 

 + Trans. Bot. Soc. Edin., vol. xiv. pi. vii. 

 \ Loc. cit., pi. xvi. fig. vi. 



