Carruthers— On Fossil Araucarian Cones, 249 



III. — On Araucarian Cones from the Secondary Beds of 



Britain. 



By Wm. Carruthees, F.L.S., of fhe British Museum. 



(PLATE XI.) 



THE unsatisfactory condition of palfeontological botany arises 

 from the imperfect materials which are obtained from the earth's 

 strata. With the exception of two or three remarkable structures, no 

 histological characters ha^e been found whereby the position of a plant 

 can be determined from an examination of its woody structure ; so 

 that silicified or calcified woods, which are far from rare, supply 

 little more information than that they are portions of a vascular cryp- 

 togam, a palm, a conifer, or other exogen. Of leaves also it may be 

 said that, while a very few natural families have characteristic 

 forms, yet leaves which are undistinguishable are foimd belonging 

 to plants widely separated in the vegetable kingdom, so that we have 

 little confidence in determinations made from them ; indeed, such de- 

 terminations must be considered at the best but as guesses at the 

 truth, and these can seldom go further than the natural order, or, 

 perhaps, the genus to which the fossil belongs. To manufacture 

 species on no other characters than those obtained from slight 

 variations ia the form of the leaf, is a reckless multiplication 

 of names, condemned hot only by the botanist, but by every 

 one who has carefully examiaed the variety in form and vena- 

 tion that exist among the leaves of a single shrub or tree. The 

 organs employed by systematists in the classification of plants 

 are so delicate, and so easily perish, that they are very rare as 

 fossils. Fruits, however, are more abundant, and after the flower 

 they may be held of next value in determining the affinities of a 

 plant. Even the separated seeds of living species, or members of 

 living genera, can be positively determined ; but when the affinities 

 are obscnre, the more or less imperfect specimens of fossil seeds de- 

 tached from their fruits are very unsatisfactory materials. 



There is, perhaps, no order of plants in which the compound fruit re- 

 tains its entirety so well as in Goniferce, and consequently perfect cones 

 are not unfrequently found as fossils. The two which we purpose to 

 describe in this paper are not based upon detached seeds, but upon 

 seeds so aggregated as to exhibit the cone arrangement of the genus 

 Araucaria. A third specimen has been found, but, unfortunately, I 

 have not been able to discover in whose possession it now is. Dr. 

 Eitton refers to it ia a note to his elaborate paper on " The Strata 

 below the Chalk." (Trans. Geol. Soc. 2nd Ser., vol. iv., p. 348.) 

 He says it was found on the shores of the Isle of Portland, and not 

 improbably derived from one of the beds of clay or " dirt," subor- 

 diuate to the lower part of the Portland strata. Dr. Eitton had the 

 loan of it from the Eev. D. Williams, of Bleadon, Somerset, and sub- 

 mitted it to Mr. Eobert Brown, who was satisfied as to its affinities to 

 Araucaria. Mr, Brown, unfortunately, did not carry out his inten- 

 tion of describing it. The cone does not exist ia his collection of 



