58 GINKGOALES [CH. 



confirmation of this and an examination of some of Heer's material 

 lent to me through the kind offices of Dr Zalessky failed to reveal 

 any indication of spores or sporangia. In Heer's Antholithus 

 Schmidtianus the lateral appendages are said to bear 3 4 pollen- 

 sacs in a terminal whorl, but Heer also suggested the possibility 

 that these bodies are the segments of a calyx-like envelope, a more 

 probable interpretation. It may be that the terminal bodies are 

 homologous with the slightly expanded distal ends of the append- 

 ages in S. lepida and possibly with the collar at the base of the 

 ovules of GinJcgo biloba, which in the case of S. Schmidtianus has 

 the form of a lobed cupular organ which enclosed a seed. It is 

 noteworthy that Heer's figures show a central scar surrounded by 

 the spreading lobes. 



The incomplete Jurassic specimens from Victoria (Australia) 1 

 described as possibly parts of a female shoot of a Ginkgoaceous 

 plant resemble Stenorachis lepida and should be referred to the 

 same genus. 



A specimen like those represented in fig. 657 has been figured 

 by Krystofovic 2 from Jurassic rocks in Ussuriland as Ginkgo sp. 

 An imperfect fossil described from Jurassic beds in Australia as 

 possibly a seed-bearing shoot of a Ginkgoaceous plant 3 should be 

 included in Stenorachis, as also Raciborski's Ixostrobus Siemirad- 

 zkii* from Rhaetic beds of Poland. 



In no case have we any decisive evidence with regard to the 

 parentage or morphological nature of the specimens referred to 

 Stenorachis, but any material that may represent fertile shoots 

 belonging to Ginkgoales or Cycadophyta should be described in 

 the hope that additional facts may be obtained. 



ERETMOPHYLLUM. Thomas. 



A genus founded 5 on some well-preserved leaves from the 

 Middle Estuarine (Middle Jurassic) beds of Gristhorpe Bay on the 

 Yorkshire coast, and named Eretmophyllum from the paddle-like 

 form of the lamina 6 . Leaves oblanceolate to linear reaching a 

 length of 12 cm. and a breadth of 2 cm. ; in the type-species, 



1 Seward (04 2 ) B. p. 179, figs. 39, 40. 



2 Krystofovic (10) PL m. fig. 5. 3 Seward (04 2 ) B. PL xix. 



4 Raciborski (92) PL n. figs. 58. 



5 Thomas (13). 6 eper/m-ov. a paddle. 



I 



