28o STUDIES IN FOSSIL BOTANY 



Fig. iog.— Group of Palaeozoic fructifications of Ferns or Pteridosperms. A. Asterotheca 

 (probably Marattiaceous). i. Fertile pinnule showing eight synangia. Enlarged. 

 2. Synangium in side-view ; 3. in section (diagrammatic). After Stur. B. Renauitia, 

 Zeiller (affinities doubtful). 1- Pinnule, showing sporangia on veins. Nat. size. 

 2. Single sporangium. Enlarged. After Zeiller. C. Dactylotkeca (affinities 

 doubtful). 1. Pinnule, showing sporangia on veins. Nat. size. 2. Single sporangium. 

 Enlarged. After Zeiller. D. SUi-riella, Weiss (cf. Corynej>teris). Transverse 

 section of pinnule, showing a synangium. a, vascular bundle of pinnule ; c, hairs ; 

 b, d, annulus of confluent sporangia. X 8. After Renault. E. Oligocarfiia (cf. 

 Gleicheniaceae). Sorus in surface-view. Magnified. After Stur. F. Crossotheca 

 (<5 of Lyginodendreae). Fertile pinna, bearing several pinnules with sporangia. 

 Enlarged. After Zeiller. G. Senftenbergia (cf. Schizaeaceae). Tip of fertile 

 pinnule, showing five annulate sporangia. Magnified. After Renault. H. Hawlea 

 (probably Marattiaceous). Synangium, after dehiscence of the sporangia. Magnified. 

 After Stur. J. Umatopteris (affinities doubtful). 1 Part of fertile pinna. Nat. 

 size. 2. Sporangia, enlarged, showing apical pores. After Kidston. 



