108 



ROYAL SOCIETY OF CANADA 



examples of the stems of this species, being three to a centimetre near 

 the base, and four to a centimetre on the rest of the stem. The fol- 

 lowing figures show the relation of the width of rib to the position 

 on the stem. 



Length of internodes in mm 4 5 8 10 16 26 30 36 40 40 41 41 45 



Number of ribs toi centimetre.... 3^ ^ 'Sh 3^ 3^ 4 4 4^ 4i 4^ 5 5 5 



The long diameter of the stem is 50 mm. 



A flattened example of the same width as the above from this mine 

 has a much stronger curve from the base where it is more acutely pointed 

 than the preceding example. 



Length of internodes in mm .... 3 7 10 14 20 23 28 32 26 40 50 50 

 Number of ribs toi centimetre.... 10 6i 5 4 4 4 3i 4^ 4i 4^ 5 5^ 



The basal joints in the stem are more elongated than in the 

 former, which perhaps may account for the more numerous ribs there. 

 In the upper part of both stems the elongation of the joint is accom- 

 panied by a slight narrowing of the ribs. 



Sculpture. — The surface of the epidermis in this species is very 

 finely striated longitudinally; these strise nearly abut against the lower 

 side of the leaf scars, which are large and oval, or round, and are placed 

 at the upper ends of the ribs; but the strise draw together and unite 

 above the leaf scar, becoming more prominent; on the surface of each 

 rib there are about thirty of these fine striœ. 



The stem is also marked with fine longitudinal striœ beneath the 

 bark, but less distinctly than on the surface of the latter. In this it 

 differs from Asterocalamites and Calaraodendron in which the striation 

 and ribhing are strongest on the inside of the ligneous cylinder. 



The following are dimensions of examples of 0. Sucl'ovii from the 

 Little Eiver group : — 



Horizon 



and 

 Locality 



Number 

 of ribs 

 to 1 cm. 



F.L. 



Lower 

 Cordaite 



Murphy's Pt., \ 

 Up. Cordaite/ 



F, L., Lower 1 

 Cordaite . . . / 



Dadoxy lon^l 

 Sandstone, > 

 Duck Cove J 



Homotypes in Nat. Hist.^ 

 Soc. coll'n, under the I 

 name of C. cannœ- j 

 formis J 



Highest sub-flora of Little \ 

 River group / 



Second sub-flora of Little) 

 River group / 



First sub-flora of Little t 

 River group 1 



3-4 

 3-3^ 



4 

 3è 



