116 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



This genus is only known from a few specimens showing 

 structure which were found in the well-known "Coal-Balls." Of 

 Spencerites insignia four examples seem to have been discovered, 

 but of Spencerites majusculus only one is known to exist. The 

 first-named species has been met with near Halifax and Hudders- 

 field, the latter near Halifax. 



SPHENOPHYLLALES. 



Sphenophyllum, Brongniart, 1822 (1828). 



1822. Sphenophyllites, Brongniart. Class, d. veget. foss., pp. 



9 and 34. 



1823. Rotidaria, Sternberg. Essai flore monde prim., I., fasc. ii., 



pp. 34 and 37; fasc. iv., p. 32. 



1828. Sphenophyllum, Brongniart. Prodrome, p. 68. 



1864. Sphenophyllum, Coemans and Kicks. Monographic des 

 Sphenophyllihm d' Europe. Bull, de V Acad. Roy. des 

 Sciences, Brussels, Vol. XVIIL, 2 e Ser., pp. 134-160. 

 Pis. I.-II. 



1893. Sphenophyllum, Zeiller. Etude sur la constitution de 

 Vappareil fructificateur des Sp)henophyllum. Mem Soc. 

 Geol. de France, Vol. IV., No. 11, pp. 1-39, Pis. 

 III.-V. 



1895. Sphenophyllum, Williamson and Scott. Further Observa- 

 tions on the Organization of the Fossil Plants of the Coal 

 Measures. Phil Trans., Vol. CLXXXV., pp. 919-946, 

 Pis. LXXV., LXXVL, LXXXIII., LXXXIV, 

 LXXXV. 



Plants with slender stems, apparently not attaining to large 

 dimensions. Branches irregularly given off at considerable 

 intervals, and not more than one from a node. Stems ribbed 

 with tumid or swollen nodes, ribs not alternating at the nodes, 

 but continuing in the same line. Internodes varying in length. 

 Leaves polymorphic, rarely narrow lanceolate, generally cuneiform 

 in outline, entire or much divided into segments, segments wedge- 



