CARBONIFEROUS LYCOPODS AND SPHENOPHYLLS. 10 



Of specimens of Stigmarian stools which cannot be definitely 

 referred to their parent genus, some very fine examples are given 

 by Williamson in his " Monograph of the Morphology and 

 Histology of Stigmaria Jicoide^." ^ His figs. 3-4, PI. II., exhibit- 

 ing the under surface of stools, show the cross-formed furrow 

 caused by the growth of the four arms pressing on each other. 

 This is even better seen on his figs. 5-6, PI. III., where the 

 Stigmarian rootlet-scars are preserved. 



Possibly the finest specimen of Stiymaria yet discovered was 

 that found at Clayton, near Bradford, and now in the Museum of 

 Owens College, Manchester. This specimen has been described 

 several times, but no more accurate description or admirable 

 figure can be found than that given by Williamson." One of 

 the chief interests of this specimen was the opportunities it 

 afibrded for a careful uncovering of all the main rhizomes, and in 

 one case they were able to trace one of them to its termination, 

 when the entire length was found to be 37 feet 4 inches. All 

 Stigmaria rhizomes which have been carefully traced, as far as I 

 am aware, only show two bifurcations, and the portion of the 

 rhizome referred to above, when measured from the last bifurca- 

 tion, was 28 feet long. It was also found to terminate in a sharp 

 point, a character which had been previously mentioned by 

 Piichard Brown, svho, in the description of some Stiymaria 

 rhizomes, says : " Two of the roots, it will be observed by fig. 3, 

 have been followed to their terminations, where they gradually 

 thinned out to a mere line in one direction, being about three- 

 fourths of an inch in width." -^ 



Now it is a very remarkable circumstance, when taken in con- 

 nection with what has just been stated, that the termina- 

 tions of some Stiymaria rhizomes which have been described and 

 figured, have blunt apices " like thick cucumbers." Steinhauer 

 gives one, * and Goldenberg gives another, though his example ^ 



1 Pakeont. Soc. for 18S6 (1887). 



- " Monog. Stigmaria," Palceont. Soc, 1887, PI. XV. 



3 Brown, Quart. Journ. Geol. Soe., Vol. II., p. 396. 1846. 



* Trans. Amer. Phil. Soe., 1818, PI. IV., fig. 3. A'o^e.— Itis impossible 

 to decide from the figure whether the specimen is a Stigmaria or Stig- 

 mariopsis. 



^ Goldenberg, Flora Sarcepont. fois.. Heft. 3, p. 15, PI. XII., fig. 3, 1862. 



