370 PKOCEEDJXGS OF THE GEOLOGICAL SOCIETY. [March 12 , 



Lepidodendron LePTOPHWEUM 



gaspianum. ehombic-um. 



Stems and branches Long and slender ; areoles Short and stout ; areoles 



elongate-lanceolate. regularly rhombic or 

 transversely rhombic. 



Vascular scars In middle of areoles, or Always in middle of 



nearer upper end, ac- areole. 

 cording to surface ex- 

 posed. 



Leaves Short and much curved Long and somewhat 



outward. straight and erect. 



Fruit Small, scaly. Long, leafy. 



Structure Unknown, but probably Known to possess a 



allied to Carboniferous large Sternbergia-pith 



Lepidodendron. and to have a very 

 thin cortical layer. 



The author reasserts his original opinion of the structure of the 

 leaves and fruit of his Leptophlosum rliombicum, which Mr. Carru- 

 thers supposed him to have given up from its not appearing in more 

 recent papers. 



With respect to the Sternbcrgia-^ith. of Leptophlosum, Dr. Dawson 

 states that he has complete and decorticated specimens of the 

 branches and specimens showing the Sternbergia-Tpith quite exposed. 

 The vascular scars are in the middle of the areoles in both the inner 

 and outer surfaces of the bark, owing to the thinness of the bark 

 (alluded to in the name Leptophloeum). 



Dr. Dawson remarks that the group to which Presl gave the 

 name of Bergeria is Carboniferous, and not Devonian, and that it has 

 no special affinity with Leptophlosum or L&pidophloios, and he regards 

 Mr.Carruthers's application of that name as objectionable, and tending 

 to produce doubt and confusion. 



With regard to the identity of the Australian specimens with 

 those from Canada and Maine, Dr. Dawson does not venture to 

 pronounce an opinion ; but he suggests that the Australian plant 

 may be a Leptophlosum, although, if Mr. Carruthers's interpretation 

 is correct, he thinks it ought to be placed in a new genus. 



Discussion". 



Mr. Cakeuthees observed that, in investigating the plants sub- 

 mitted to him by Mr. Daintree, he could only deal with published 

 observations and drawings in correlating them with known forms. 

 He considered that each systematic worker was at liberty to review 

 the conclusions of previous authors; and if he saw reasons for 

 doing so, to treat their names as synonyms. In Lepidodendron 

 nothum, of linger, the leaves are unknown ; but the leaf-scars are 

 rhombic, and the decorticated portion of the stem is marked with 

 oval vascular scars. Principal Dawson, in his Lepidodendron gas- 

 pianum, figures two kinds of leaves, one short and erect, the other 

 longer and outward-curved ; and he showed the external leaf-scars 

 to be rhombic, and the decorticated condition to have oval markings, 

 both exactly as in L, nothum, of linger. No foliage or fruits of 



