The Fossil Plants of the Coal Measures. 125 



from the Lcpidodcndroid type. Besides these I subsequently 

 obtained three other fragments; one of SigillariaReniforviis, 

 of which a part of the primary tracheal cylinder is preserved 

 (C.N. 651-652), along with a corresponding portion of its 

 secondary xylem strand. A second one was of the 

 RJiytidolarian type. The third was a Szgillaria, also belong- 

 ing to Brongniart's i^igillarce verce. Tangential sections 

 of this specimen shew clearly (C.N. 662) the transverse 

 sections of the leaf-trace and its two vertically elongated 

 parichnoid organs. The transverse section of the tracheal 

 cylinder (C.N. 651) is important, because it is identical with 

 a perfect cylinder in my cabinet detached from its cortical 

 structure, and figured in Memoir II., fig. 33. This cylinder 

 consists of a primary tracheal cylinder enclosed within a 

 secondary xylem strand one — the line of junction between 

 the two being a crenulated one. This corresponds with 

 what Brongniart found in his '' Sigillaria Elegans" (really 

 8. Menardii), as also did M. Renault in his ^. spinulosa. 

 In addition to these few examples Mr. Carruthers has 

 long had in his possession a similar specimen in which 

 the cortex and the two central tracheal structures are 

 excellently preserved. 



SIGILLARIA.— FAVULAKIAN TYPE, 

 Vertical Section. 

 Medulla. 



B. —p. 211, Figs. 29 and 31a, C.N., 684. 



Primary Tracheal Cylinder. 



B. — p. 211, Fig 3id., C.N. 684. 



Cortical Pkosenxhym.e. 



B- — p. 211, Fig. 29dd,* Fig. 3ig., Fig. 32k, C.N. 684. 

 Fig. 30k {transveise) C.N. 685. 

 Outer Cortical Parenchyma and Leaf-Cushions. 

 B. — p. 211 {longitudinal). Fig. 32I, C.N. 684. 

 p. 211 ( transverse). Fig. 30I, C.N. 685. 

 Leaf-Cushions and Strobiloid Scars, Tangential. 

 B.— p. 211, Fig. 58, C.N. 678.— A cast. 



* The left-hand d should point a little further to the left. It now points to some 

 Tracheids of the primary cylinder. 



