62 CONIFERAE. 



has recently made us acquainted with a phylloclade bearing seeds from the 

 Upper Chalk of Spitzbergen, which he names Phyllocladus rotundifolius, 

 Heer. Without a knowledge of the original specimen it is impossible to say 

 whether this determination can be justified or not. Lastly, Schenk l has 

 suggested a comparison of his Conchophyllum Richthofeni from the Coal- 

 measures of China with the female spikes of Dacrydium, though he is not 

 prepared to place it with Dacrydium ; for the present this fossil also must 

 remain quite doubtful. 



Bertrand 2 has described some carbonised shells of seeds found in local 

 deposits filling pockets in the Cenomanian limestones above the Wealden 

 formation of Tournay in Belgium, which from their structure he places be- 

 tween Cephalotaxus and Torreya, and names Vesquia Tournaisii. He shows 

 that these two genera are the only living forms of Taxineae in which two 

 vascular bundles traverse the integument or shell of the seed, and that they 

 are distinguished from one another by the distance which the two bundles, 

 which occupy the margins of the seed, run in the woody layer of the seed- 

 coat. Vesquia shows a similar structure ; the bundles are destroyed, and in 

 their places a canal runs throughout the whole length of the hard seed-coat ; 

 but there is still the possibility that the seeds in question may have belonged 

 to one of the many Salisburieae of that epoch, Baiera, or Phoenicopsis, or 

 Feildenia. If Ginkgo itself has no vascular bundles in its integument 3 , this 

 is no proof, as the comparison of Taxus with Torreya shows, that there could 

 have been no bundle in those older allied forms. 



Ginkgo biloba, the single living type of the Salisburias, stands, as we 

 know, alone, a perfect stranger, in the midst of recent vegetable forms. The 

 tree, unknown in the wild state and preserved only in the groves of Chinese 

 temples, seems to have been kept from extinction by the care of the priests. 

 But it is almost certain that it is really the survivor of a series of allied 

 plants which was rich in species and individuals. The merit of supplying 

 proof of this belongs to Heer 4 . It is true that some of these forms were 

 already known, having been found in different formations from the Rhaetic 

 beds upwards, but they had been taken for Ferns and had been generally 

 described as Cyclopteris and Baiera. Of these forms Heer at first selected 

 two especially, which are figured in Brongniart 5 as Cyclopteris digitata, and 

 in Lindley and Hutton 6 under the same name. Heer distinguished these as 

 Ginkgo digitata, Heer, and G. Huttoni, Heer, on the strength of his material 

 from the Lower Oolite of Spitzbergen in which he recognised them, and 

 added some other species to them. That these leaves were not the pinnate 

 leaves of ferns he concluded from their long stalk, on which the lamina 



1 Schenk (2), t. 42. 2 Bertrand (1). 3 C. E. Bertrand, Etudes sur les teguments seminaux 

 des vegetaux phanerogames gymnospermes, in Ann. d. Sc. Nat., ser. 6, vol. vii (1878), p. 70. 

 4 Heer (1) and (5). 5 Brongniart (1), vol. i, t. 61, ff. 2, 3. ' Lindley and Hutton (1), vol. i, t 64, 



