CONIFERAE. 59 



work to enter more closely into their consideration. Thirdly and lastly, 

 Sequoia Sternbergii, Heer, a species resembling S. gigantea in foliation, and 

 one of the best known and commonest forms, especially in Miocene times ; 

 but its connection with the Sequoias has been recently questioned. 

 Marion l sees in it the type of a peculiar genus known as Doliostrobus 

 (D. Sternbergii), and Renault 2 assents to his view. Respecting the English 

 plant known as Cryptomeria Sternbergii, Gardn. 3 , and identified with a part 

 at least of the remains which are associated by authors with the Sequoias, 

 I do not venture to express an opinion. It comes from the ' basaltic for- 

 mation' of Ireland ; its cones are plentiful but never found attached to the 

 branches. These cones, as well as the one figured by Heer 4 , do not in 

 fact look excessively like those of Sequoia. 



Velenovsky's new genus Ceratostrobus, with two species, C. sequoiae- 

 phyllus and C. echinatus, is closely allied, according to that author 5 , with 

 Sequoia, standing between it and Cryptomeria. The scales of the small 

 spherical cones in this genus have a long thorn-like process in the middle 

 of the apical areola. In both species cones and branches have been found 

 attached to one another ; the habit of the latter is to some extent that of 

 Sequoia gigantea. 



The genus Taxodium, wonderfully like Sequoia sempervirens in the 

 structure of the lateral branches which are deciduous in autumn, is, like 

 Sequoia, very widely diffused through the Tertiary formations from the 

 Oligocene upwards; the detached branchlets and the very characteristic 

 cones are both found, and are so like those of the living species that most 

 authors are unwilling to separate the fossil form from it, and therefore speak 

 of Taxodium distichum miocenum. According to Heer 6 the leafy branches, 

 though resembling those of Sequoia Langsdorffii, are however distinguished 

 from it by not having the decurrent leaf-cushions of Sequoia. Good figures 

 of the fossil cones will be found in Heer 7 . 



Lastly, Glyptostrobus is abundant also in the Tertiaries from the Oli- 

 gocene upwards. Two species are distinguished, G. europaeus, Heer, and 

 G. Ungeri, Heer, besides two less certain forms. The highly characteristic 

 cones are very often attached to the branches which bear them. They are 

 figured in Schenk 8 and in Unger 9 . Heer 10 has described various small 

 fragments of branches from the Chalk of Greenland, which are supposed 

 to belong to Glyptostrobus ; there is a figure also of a cone-scale from 

 the Urgonian beds of Kome in Greenland, which though somewhat 

 obscure and not in good preservation, yet may probably be classed with 

 Glyptostrobus. 



1 Marion (1). 2 Renault (2). 3 Gardner (1) (1884), p. 85, t. 10. 4 Heer (10). p. 310. 

 5 Velenovsky (1), t. 12, ff. 15, 16, and t. n, ff. 12, 15. Heer (11). 7 Heer (12), t. 2. 



Zittel (1), p. 296. 9 Unger (3), t. i, ff. 3-1 1. 10 Heer (5). 



