FLORA OF TIIK SHASTA FORMATION. 275 



The cciilinl part of the medulla has decayed out, leavino; a deep cavity 

 Of hollow 7 cm. deep and (i by 10 cm. in diametei-. The whole interioi- 

 seems to he pui'c silica, and strong hydrochloric acid produced no reaction 

 wIhmi a|)i)lie(l to the fi'actui-c at the sunmiit or to the smooth ha.'^e, hut 

 ovei' the rest of the sui'facc thei'c was a calcai'cous wash without appre- 

 ciable thickness, anil when innners(>(l in an acid hath it was removed 

 without materially altei-in<i the ti.'^sues or chanf!;in<i the color. 



The trunk stands '2'A cm. high, and the diameters at the base are 

 17 cm. and 34 cm., I'espectively, giving a girth of S() cm. .About midway 

 of the ti'unk the girth is I'educed to 7S cm., and near the sunmiit to (10 cm. 

 Here it is much more flattened, the minor diiimeter being only ."> cm. 

 It weighs 58.47 kg. The I'emaining chai'acters are specihc and will be 

 described as such. 



The genus Cycadeoidea has been referred to an older distinct fiom 

 the Cycadales and called the Bennettitales, and to a family distinct 

 from the Cycadacesp, called the Bennettitaceae. The reproductive 

 organs, according to Solms-Laubach, indicate a less advanced type of 

 vegetation than the living Cycadace*," and they should therefore precede 

 the latter in the ascending order according to the classification of Elngler 

 and Prantl adopted in this paper. It should, however, be remarked 

 that the reference of the leaf impressions of cycadaceous fossil plants to 

 the Cycadacea^ is made on account of our ignorance of their true system- 

 atic; position, as no reproductive organs are fomid attached to them. It 

 is altogether probal^le that the trunk here described bore the leaves of 

 some of the genera found in the same beds, but it is impossible to deter- 

 mine which one of them. It will probal)ly prove, should the connection 

 ever be made, that nearly all Mesozoic genera of cycads really belong to 

 the Bennettitales. 



I am unaljle to refer the present trunk to ;my of the species of 

 Cycadeoidea hitherto described, and am therefore obliged to regard it 

 as forming a new species. I name the species after its discoverer, Di-. 

 T. W. Stanton. 



" Mr. W^or.sdell lia.s cotiic tii tlio contnirv conclusion, but upon evidence wliidi, .so fara,s I am eapableof 

 wei};liing it, is not satisfaclory. Tlie aflinities of the Mesozoic fossil Brnniltites Gibsonianus Carr.jUy W.C. 

 Worsdeli. Annals of Botany, Vol. XIV, No. ,50, Dcccnilier, 1!KK), pp. 717-721. 



