46 



GINKGOALES 



[CH 



referred this type to Schizopteris but Bunbury, while adopting 

 Bean's MS. specific name, substituted the generic designation 

 Baiera. The leaves are petiolate and the lamina is divided almosl 

 or quite to the base into a varying number of linear segments 

 with obtuse apices. The veins, frequently indistinct, run parallel 

 to the edges of the lamina and there are several in each segment. 



Leaves identical with or very similar to Baiera gracilis are 

 very widely distributed among Jurassic floras in both hemispheres. 

 Some of the specimens described by authors as Ginkgo lepida are 

 hardly distinguishable from Bunbury's species ; G. concinna 1 Heer 

 from the Siberian Jurassic flora is another very similar form; 

 also Baiera incurvata Heer 2 from the Lower Cretaceous of Green- 

 land, B. angustiloba Heer 3 , as figured from Siberia and China, 

 B. bidens (Ten. -Woods) 4 from Queensland, B. australis McCoy and 

 B. delicatula Sew. from Jurassic rocks in Victoria 5 , also leaves 

 recently referred by Halle 6 to B. australis from the Lower Cretaceous 

 plant-beds of Patagonia. Baiera gracilis is recorded from Upper 

 Jurassic (or Lower Cretaceous) beds in Alaska 7 , but leaves of this 



FIG. 651. Baiera gracilis forma Mucnsteriana. 

 (British Museum, f nat. size.) M. S. 



type are rare in the Jurassic strata of North America. The 

 Khaetic species B. Muensteriana* (Presl) described by Schenk from 

 Franconia and by other authors is a closely allied type which 



1 Heer (77) ii. PI. xm. figs. 68. 2 Ib'd. (82) B. PI. xm. fig. 6. 



3 Ib'd. (78) ii. PL VTI. fig. 2; Krasser (05) PL n. fie. 10; Schenk (83) A. PL LTII. 

 fig. 1. 



4 Tenison- Woods (83) A.. PL TV. fig. 3. 



5 Seward (04 2 ) B. figs. 3638. Halle (13) Pis. iv., v. 

 7 Fontaine in Ward (05) B. PL XLIV. fig. 2. 8 Schenk (67) A. PL ix. 



