I 



302 Mr. It. Kidston on the Affinities of the 



The three following specimens have been already described 

 by Mr. K. Etheridge, Jim. ; but as they show some points of 

 considerable value as regards the affinity of the genus Potho- 

 cites, I give a description of them here in full. 



Pothocites Pater soni) K. Eth., Jun. 



(PL X. figs. 6, 7, 8, PI. XI. figs. 9& 10, PL XII. fig. 14.) 



Pothocites Patersoni, E. Etheridge, Jim., " Note on the Further Dis- 

 covery* of a Species of Pothocites (Paterson) in the Lower Carboni- 

 ferous Eocks near West Calder," Trans. Bot. Soc. Edinb. vol. xii. 

 p. 151 (1874). 



Of this plant we have four specimens, representing two 

 individuals. That figured on PL X. figs. 6 and 7, and 

 PL XII. fig. 14, was obtained by Mr. James Bennie, fossil- 

 collector to the Geological Survey of Scotland, from the black 

 bituminous shale which overlies the oil-shale worked at Rae- 

 burn's Pit, near Gram's Green Toll-bar, about a mile and a 

 quarter north of West Calder. 



The specimen, which is represented by the fossil (fig. 6) 

 and the impression (fig. 7), measures in its full length three 

 inches and three quarters. Four segments of this spike are 

 shown ; but it is imperfect towards its upper extremity. 



This is proved by the central axis extending slightly past 

 the last segment which has been preserved. 



From the proportion which the uppermost segment bears to 

 the other segments of the fruit it is probable that there originally 

 were not more than two additional parts in the entire spike. 



Of the whole length of the specimen the spike occupies about 

 two inches and three fifths. The basal segment measures 

 four fifths of an inch in length by three eighths of an inch in 

 breadth. The segments decrease slightly in length and 

 breadth as we recede from the base, the fourth being only 

 seven sixteenths of an inch long and a quarter of an inch 

 broad at its base ; but it is somewhat narrowed at its apex. 

 This narrowing of the segments at their apices, as will be 

 shown in a specimen presently to be described, is only exhi- 

 bited in the terminal portions of the fruit; the breadth of the 

 lower segments in all the specimens is almost uniform 

 throughout their entire length. 



From the amount of pressure to which this specimen has 

 been subjected, it is a matter of considerable difficulty to 

 determine accurately the number of the longitudinal elevated 

 ridges on each segment j but they appear to have had on their 

 exposed surfaces six such rows, which run continuously 

 through all the segments. 





