152 Prof. Dyer — On Oolitic Coniferce. 



In Araucana there is at first sight the j)eculiarity that the scales 

 borne by the primary axis of the cone are themselves those which carry 

 the single seeds (see Figs. 4:h. and 5) . This is an important difference ; if 

 the scales of the primary axis bear the seeds, then those botanists who 

 refuse to admit the existence of a carpellary covering distinct from the 

 seed-bearing scale, would be obliged to regard the whole cone as equi- 

 valent to a single flower. If, however, the seeds are borne in the 

 leaves of secondai*y axes, the cone must, on any view, be looked upon 

 as an inflorescence. Professor Dickson has, I think, shown ^ that 

 the structure of the Araucarian cone corresjDonds with that of Pinus, 

 the difference being that in Araucaria the two scales are confluent. 

 The combined scale has a more or less well-marked double apex 

 which is shown very evidently on Figs. 4&. and 5 ; the meaning of 

 this on any other than Professor Dickson's view is inexplicable. 



Longitudinal Section of Scale of Araucaria BidwilliP' 



The genus Araucaria has been divided into two sections ; in 

 Columbea the scales are destitute of the winged margin, which is 

 characteristic of Eutacta. The two species of Araucarites which 

 Mr. Carruthers has founded upon scales from the Lower Oolite both 

 belong to the latter section. To this must also be referred the Upper 

 Oolite species from Solenhofen. At first sight it might be supposed 

 that the inner outline shown in Figs. 1-3, belonged to the upper or 

 seed-bearing scale. This, however, cannot certainly be concluded, 

 as it only marks the commencement of the wing. Fig. 2 shows the 

 apiculus or minute free portion of the upper scale {lepidimm of 

 descriptions). 



The Solenhofen scales exhibit very evidently the remains of the 

 fibro-vascular bundles ; they can only be demonstrated in recent 

 scales by maceration. It would therefore seem that the scales must 

 have undergone a considerable amount of decay before final inclo- 

 sure in the material of their present matrix. Zuccarini * has studied 

 the arrangement of these bundles. According to his observations, 

 in the seed-bearing scales of Pinus " the rays proceeding from the 

 principal vascular fasciculus converge again towards the apex," and 

 present a distinctly dichotomous arrangement (p. 36). The dicho- 

 tomy, however, takes place in Pinus close to the bottom of the scale, 



1 Edin. New Phil. Journ., 1861, pp. 198, 199. 



2 Geol. Mag., 1866, p. 261. 3 Eay Soc. Rep. and Pap., 1845. 



