XLj GINK60ITES 13 



ohovata : the obovate lamina is 5-6 cm. long with a maximum 

 breadth of 2-5 cm. ; the upper edge is partially torn and the 

 forked veins are about 3 mm. apart. Some dark patches between 

 the veins are probably, as Nathorst suggests, secretory sacs 

 similar to those in the leaves of Ginkgo. In shape but not in 

 venation this type resembles Ginkgodium Nathorsti Yok.^ (fig. 659, 

 p. 62) ; except in the absence of a deep median sinus it is, how- 

 ever, nearer to a species from the Jurassic of Dzungaria described 

 originally as Ginkgo Obrutschewi^ (fig. 642, p. 26). 



Ginkgoites Geinitzi Nathorst. 



The leaf from the Rhaetic beds of Scania on which this species 

 was founded was originally referred by Nathorst^ to Ginkgo but 

 subsequently transferred by him to Baiera ; it consists of a slender 

 stalk and a siib-triangular lamina deeply divided into 4 — 6 linear 

 truncate segments with 2 — 4 veins dichotomously branched near 

 the base (fig. 645, B, p'. 38). An examination of the original 

 specimen leads me to prefer the designation Ginkgoites to Baiera. 

 This species like many others from Rhaetic rocks is hardly dis- 

 tinguishable from some Jurassic types. 



Ginkgoites antarctica Saporta. 



Under the name Salisburia antarctica Saporta* described a 

 single leaf from Austraha believed to be of Lower Lias age, but 

 no precise information is given with regard to the locahty. Shirley ^ 

 has also figured a specimen as Ginkgo antarctica from rocks that 

 are probably of Rhaetic age at Denmark Hill, Ipswich (Queens- 

 land). The lamina of Saporta's specimen is broadly obcuneate 

 and 3-5 cm. broad, characterised by the presence of two marginal 

 veins hke those in Ginkgo hiloba from which forked branches are 

 given off. This leaf is practically identical with some of the 

 smaller, entire, examples on the short shoots of the recent type. 

 The rather larger specimen figured by Shirley does not present so 

 striking a similarity to those of the existing species. The lack of 

 definite information as to the provenance of the type-specimen 



' See page 61. ^ Seward (11) p. 46, Pis. iii.— vi. 



3 Nathorst (78) B. p. 26, PL xm. fig. 17. 



* Saporta and Marion (85) p. 142, fig. 71, A. ; Ratte (88) PI. iii. fig. 1 ; Renault 

 (85) A. PI. II. fig. 19. 



5 Shirley (98) PI. i. fig. 1. 



