092 MR. W. CARRUTHERS ON FOSSIL CYCADEAN STEMS 



Mr. Yates, in a notice of this plant published in the ' Proceedings of the Yorkshire 

 Philosophical Society' for 1817 (p. 37), describes the inflorescence as consisting of a num- 

 bar of scales resembling sepals, petals, or perhaps dilated stamens, all growing from the 

 to]) of the fruit-stalk, and overlapping one another. They surrounded an oval or piri- 

 form cavity, which he thinks may have contained the germen. 



Prof. Williamson 1 , in the same year, suggested that the axis above the collar of leaves 

 supported a cone, which had been always broken off. M. Brongniart, to whom Mr. 

 Yates communicated his large series of specimens, and Prof. Williamson his accurate 

 drawin s, was unable to determine their affinities. He considered them to belong to an 



.tinct type, so different from any known Cycad that it is very difficult to understand 

 them. Jle further considers that the buds present some analogies to the fruit of JPodo- 



anh . a Pandanaceous fossil from the Inferior Oolite near Charmouth, Dorset 2 . In 

 endeavouring to form an estimate of these puzzling organisms, after having examined 

 the extensive series in the British* Museum, I visited Scarborough, and examined the fine 



Election in the museum there, as well as that belonging to Mr. Leckenby ; I also visited 

 the museum at York, and examined the yet finer series belommiff to Prof. Williamson, 



who, after having these fossils under his notice for thirty-six years, in the most liberal and 

 disinterested manner, when he heard that I was working at them, offered to place his 

 drawings and manuscripts at my service. The number of facts he had collected, and his 

 ingenious interpretation of them, seemed to me too important to be incorporated in the 

 v\<>rk of another; and I was fortunate enough to obtain from him the paper which pre- 

 cedi i this memoir, for communication to the Society. He has introduced a clearer appre- 

 hension f the different forms of the supposed organs of reproduction, by the suggestion 

 that the two kinds represent the different sexes, and by the discovery of a seed-bearing 

 spadix. While I see serious difliculties in associating flowers so different in their struc- 

 ture, and in their relation to the supporting axis, as those belonging to W. Gigas 

 according to Prof. Williamson's interpretation, I am unable to suggest any view of them 

 which would present fewer difficulties. The discovery of a male inflorescence exhibiting 

 the internal structure would be of immense value; hitherto the numerous specimens 

 have done little more than show the external form. The elaborate exposition of these 

 organs m the memoir preceding this relieves me of entering further into their description. 

 [n proposing toe name TFllUanrnma, I have ventured to associate with a group of the 

 ^characteristic Yorkshire fossils two men (father and son) who have larselv contri- 



most 



1 to the ^position of Yorkshire ffeolooy 



» U Dt 



or 



OUhan. and Morris, in their account of fossil plants of the Bajmahal Hills », describe 

 rr ** ^ ' *" f0Ha ^ "* «*"* of Cycade,, which a*ree with the inflo- 



of W. Qiga*. One specimen is a « striated 



fibrous disk, formed of 



A tion of closely packed tubes an-in^l : • i ' 66 



mn-'inissomruvW ■ i »****&* in a circle around a central hollow ; the outer 



in 4111 i^ somewhat lnv^ulnr Tlio «™™ /» . . . 



iww.i-.vi f„i™ ,„. , J \° lhea PP eai ' a ^eofstnationisduetoacon-eriesofclosely 



tabes or long linear vessels." This 



ith the male inflorescence of 



English secies nmi ic o • i tt s iccs vvlin wie male inflorescence oi uu 



ISngI*. p n, and H a angular confirmation of Prof. Williamson's interpretation of it 



1 fr*C« \ El Phil. ROC.1847 n dR 



laDontoloL 



Tabl. Genr. Foss. pp. 62, 88. 



XXI 



