398 STUDIES IN FOSSIL BOTANY 



up to the date of Mr. Kidston's discovery. In the 

 meantime a number of other species had been described, 

 some with the Sphenopterid and others with the 

 Pecopterid type of foliage. 



Mr. Kidston's specimens were found in ironstone 

 nodules from the Dudley Coal-field (Westphalian series) 

 (Fig. 152). The specimens are preserved in the form 



of casts, but the cavities 

 in some cases are infil- 

 trated with carbonate of 

 lime, and so retain their 

 natural form, with some 

 degree of structural pre- 

 servation. Though most 

 of the fertile specimens 

 bear no sterile pinnules, in 

 some cases the two forms 

 fig. t 53 .-c»ss^ C amni, v iausi. Fertile occur in organic connec- 



pinna in connection with sterile pinnae of t j on ( see F J„ T53) prov _ 



Spkenopterts Homnghausi (leaf of Ly- v & J o Jt f 



ginodendron\ x 2. R. S. Froma sketch ing that the CrOSSOtkeCO. 

 after a photograph lent by Mr. Kidston. 



was borne on foliage 

 identical with that of Lyginodendron. Fig. 152, from 

 a photograph, shows clearly the general structure 

 and arrangement of the fertile pinnules, which are oval 

 in form, about 2-2.5 mm - m length, and borne on stout" 

 pedicels, the mode of insertion rendering them somewhat 

 peltate. The pinnule is of some thickness, and appears 

 to be traversed by a branched vein. " Each fertile 

 pinnule usually bore six, rarely seven, bilocular micro- 

 sporangia. They are fusiform and end in a sharp 

 point." 1 The sporangia are described as convergent 



1 Kidston, Microsporangia of Pteridospermeac, p. 421. 



