X^/l //3 C* 



372 ABIETINEAE 



afftnity to the recent genus. Similarly, names such as Laricites 

 Cedrites and others implying a more precise determination than is 

 suggested by Pityites may conveniently be used either as sub- 

 generic or generic terms. 



In the account of recent Conifers allusion is made to the views 

 held by students of fossil plants with regard to the relative position 

 of the Abietineae and the Araucarineae in a chronological sequence. 

 The types selected for description are intended to serve as guides to 

 those who wish to draw conclusions from the geological records, 

 but so long as we have to trust chiefly to impressions without the 

 more certain guidance of anatomical data the inferences draw^n 

 cannot be regarded as other than provisional. The evidence of 

 fossil seeds is difficult to interpret, as its value depends on the 

 amount of importance to be attached to the occurrence of speci- 

 mens closely resembling in the form of the wing the seeds of. recent 

 Pines and other Conifers. The winged seeds of Agathis differ in the 

 shape of the membranous appendage from those of Abietineous 

 species, and the oldest winged seeds attributed to the Abietineae, 

 from Rhaetic rocks, exhibit a closer agreement with the Abietineoi 

 type. On the other hand it is questionable whether the form of a 

 wing constitutes a safe criterion of affinity. A similar difficulty 

 presented by 'winged' pollen-grains: a bladder-like extension oi 

 the exine though usually associated with the Abietineae is a 

 character which is not confined to that family. Foliage-shoots like 

 those of recent Abietineae are recorded from Rhaetic rocks and 

 later Mesozoic strata, but we have no means of determining in the 

 case of the oldest examples whether their superficial resemblance 

 to branches of Cedrus and other genera has a phylogenetic signifi- 

 cance. The generic name Pinites is applied by Renault 1 to a slender 

 branch from Permian rocks in France bearing spirally disposed 

 filiform leaves 3 cm. long apparently borne singly and directly on 

 the main axis, not on short shoots. It is elsewhere 2 suggested that 

 this specimen, Pinites permiensis, may belong to a plant allied to 

 Dicranophyllum: there is certainly no adequate reason for the 

 employment of the generic term Pinites. Similarly an impression 

 figured by Stur 3 from the culm of Altendorf as Pinites antecedens, 



1 Renault (93) A. PI. xxxn. fig. 1; (96) A. p. 377. 



2 Page 101. 3 Stur (75) A. PL xiv. fig. 4. 



