XLIl] SEWARDIA 105 



the generic name Acanthoza mites as a substitute for Cycadorachis 

 in view of the new data afforded by the English material, but it 

 seemed preferable to adopt some provisional name which did not 

 imply affinity to the Cycads. The leaflets described by Saporta 

 as Sphenoza mites latifolius are apparently identical with those 

 found in the English beds, but none of the French specimens were 

 attached to a supporting axis. The relation of spines and 'leaves' 

 suggests that the latter may be phylloclades borne in the axil of 

 modified spinous leaves, but their morphological nature cannot 

 be determined. In this connexion attention may be called to 

 Dioncophyllum Tholloni Baill. a West African shrub which bears 

 on the long shoots leaves 2 3| inches long each of which has a 

 pair of strong revolute hooks at the apex : in the axils of these 

 leaves are short shoots with larger leaves without hooks. It is 

 suggested 1 that the apparent lamina of the hooked leaves is a 

 winged petiole, the hooks representing lateral leaflets. 



Sewardia longifolia (Salfeld). 



This species was described by Salfeld 2 from the Solenhofen 

 beds (Upper Jurassic) of Bavaria as Baiera ? longifolia Heer : it 

 is founded on branches nearly 30 cm. long bearing large fan- 

 shaped deeply divided leaves, or leaf-like organs, in the axils of 

 recurved spines similar to those in S. latifolia. The 'leaves' are 

 identical in habit with those of some species of Baiera, but we 

 have no information with regard to the structure of the epidermis. 

 In view of the uncertainty as to the morphological nature of the 

 leaves or their relationship to leaves of Baiera, it is inadvisable 

 to adopt a generic title that implies affinity to the Ginkgoales. 



1 Sprague (16). 2 Salfeld (07) B. p. 195, Pis. xx.. xxi. 



