23 2 STUDIES IN FOSSIL BOTANY 



fructifications, and some, as it has turned out, rightly so, 

 but evidence of identification was not forthcoming. 

 This was supplied by M. Zeiller, for the peduncle of 

 one of the cones described by him is partly clothed by 

 acicular leaves or bracts, and where these have become 

 detached, the leaf-scars are found to lie in vertical rows 

 on the ribbed surface, and to correspond very closely 

 to the markings on the stem of definite species of 

 Sigillaria, of the Rhytidolepis type. This correlation 

 having once been effected, it became possible to 

 identify various other specimens as cogeneric, and the 

 genus Sigillariostrobus, as the fructification of Sigillaria 

 is called, now includes several species. The cones are 

 often of large size, reaching a diameter of about 6 cm. 

 (S. nobilis) and a great length. None of the French 

 specimens were complete, but Mr. Kidston has since 

 described a complete cone, from the Yorkshire coal-fields, 

 9 inches long. All the known Sigillarian cones agree 

 in having long peduncles clothed with acicular bracts. 

 The fertile part bears large, crowded sporophylls, 

 arranged spirally, or in alternating whorls. The form of 

 the individual sporophylls varies in the different species ; 

 thus in 6". Tieghemi (which shows Rhytidolepis markings 

 on the peduncle) it is broadly lanceolate and contracted 

 at the base to a narrow claw, so that only a small 

 round scar is left on the axis when the sporophyll 

 has become detached. The short claw is approxi- 

 mately horizontal in direction, while the lamina is bent 

 more or less sharply upwards. In other species, the 

 lamina is prolonged into a fine point, and may be 

 toothed or ciliate at the margins (see Fig. 96, A, 

 from one of the English species discovered by Mr. 



