108 CONIOPTERI8. 



Tympanophora racemosa. The lower pinnules, at the upper end 

 of the drawing, are subdivided into five narrow lobes terminating 

 in compressed cup-shaped indusia, in which some of the individual 

 sporangia can be indistinctly recognized. The lamina of the 

 fertile segments is rather further reduced than in 52,595 (Fig. 6). 

 Portions of sterile pinnules of the S. hymenophylloides type are 

 associated with this fertile pinna. Cf. Thyrsopteris Murrayana as 

 figured by Raciborski. The fertile segments present a striking 

 agreement with those of the recent fern DicJcsonia Bertervana, Hk., 

 shown in Text-fig. 13. 



Scarborough. Bean Coll. 



40,467. PI. XVII. Fig. 3. 



The pinna shown in Fig. 3 is drawn from a bipinnate frond with 

 long acuminate pinnae, bearing obliquely placed, narrow-pointed 

 :segments of the same form as those of Brongniart's Sphenopteris 

 hymenophylloides and 52,595 (PL XVI. Figs. 6 and 7), but 

 of smaller dimensions. This specimen appears to be specifically 

 identical with Heer's Siberian examples of Thyrsopteris Maakiana, 

 Heer, and with the Whitby specimen shown in PI. XX. Fig. 1 ; 

 it affords a good example of the smaller type of frond of the same 

 habit as the larger and more abundant specimens of S. hymeno- 

 phylloides. A specimen, identical with this, in the Leckenby 

 Collection is labelled by Nathorst Thyrsopteris Maakiana, Heer. 



Scarborough. 



PI. XX. Figs. 1 and 2. No. 2373, Whitby Museum ; labelled 

 Sphenopteris dissocialis, Phill. 



This is an important specimen as affording evidence of the specific 

 identity of the fronds with shorter pinnules and more rounded or 

 truncate divisions, and those of the form represented in Brongniart's 

 figure of S. hymenophylloides. It affords additional evidence, in 

 fact, in favour of regarding such pinnae as those shown in PI. XVI. 

 Fig. 6 and PI. XXI. Fig. 2 as identical with the type shown in 

 PI. XVI. Figs. 4 and 5 and PI. XXI. Figs. 1 and 4. The two 

 fronds, portions of which are drawn in Figs. 1 and 2, PI. XX., 

 occur close to one another on the same piece of rock, and fragments 

 of pinnae with shorter and more rounded segments, and others 

 with the more pointed segments, occur indiscriminately associated 

 together. There is also one fertile pinna like that of Figs. 6 and 8, 



