124 MBDULLOSBAE [CH. 



the seed and the vegetative organs in the structure of the hypoderm 

 as also in the structure of the secretory sacs which are particularly 

 numerous in this species. Salisbury draws attention to the close 

 resemblance between the form of T. shorensis and the seeds foimd 

 in organic connexion with pinnae of Neuropteris obliqua^. 



The species T. corrugatus described by Eenault^ bears a close 

 resemblance to T. shorensis. 



Other Genera founded in part on Reproductive Organs 



WHICH MAY BELONG TO THE MeDULLOSEAE. 



Codonotheca, Schtitzia, Whittleseya, Dolerophyllum, Otto- 

 karia, Strobilites. 



CODONOTHECA. Sellards. 



Codonotheca caduca Sellards. This genus was founded on 

 some spore-bearing bodies from the Coal Measures of Ilhnois': 

 nothing is known as to the plant which bore them, but Sellards 

 is inchned to associate them with Neuropteris decipiens Lesq.*, 

 a species abundant in the same coal-field. Whatever may have 

 been the parent-plant it is probable, as the author of the genus 

 beUeyes, that Codonotheca is the microspore-bearing organ of a 

 Pteridosperm. As shown in fig. 427, 5, the form is that of a stalked 

 cup consisting in the basal portion of a stout axis, the peripheral 

 tissue of which is beheved to have been fleshy, containing an 

 axial rod of conducting tissue running up to the floor of the cup, 

 c, and then dividing into six vascular strands, each of which forks 

 into two branches. The upper part is composed of six hnear 

 segments united basally to form the sloping surface of the cup. 

 On the inner face of each segment is a more or less well-defined 

 depression covered with large elUptical spores -29 — 31 mm. long 

 by -18 — 19 mm. broad (fig. 427, 6, 8). The presence of a median 

 ridge (fig. 427, 8) indicates a bilateral origin. ' There is no grouping 

 of the spores or other indication of the location of the sporangia, 

 which were doubtless more or less completely immersed in the 

 tissue, the dividing wall disappearing at maturity.' The spores 



^ See page 115. 



2 Renault (96) A. p. 399; (93) A. PI. Lxxxv. fig. 9; Salisbury (14) p. 66. 



3 Sellards (03) p. 90; (07). 



4 Lesquereux (80) A. p. 93 ; (84) A. p. 733, PI. xciv. figs. 1, 2. 



