146 CaiTuthers — On a Fossil Aroideous Fruit. 



n. — On an Aeoidisous Fkuit fkom the Stonesfield Slate. 



By Wm. Carruthers, F.L.S., of the British Museum. 



(PLATES VIII., Figs. 2 & 3.) 



I OWE my acquaintance with, this interesting fossil to Mr. S. 

 Stutterd, who kindly forwarded it to me for my inspection. 

 It is from the Stonesfield Slate, and is preserved in limestone, 

 but is only a cast formed in the matrix left in the rock after the 

 organism itself had disappeared. The core had been hollow, or 

 composed of a more speedily perishable material than the parietes, 

 and so it rapidily disappeared, permitting the empty axis to be filled 

 with fragments of shells and calcareous sand. Externally, the 

 cylindrical fossil is formed of sub-quadrangular peltate plates, 

 with irregular undulate dentate margins, the projections of each 

 of which fit Lato the imdulations of the suiTOunding plates, and 

 are arranged in linear series. A transverse section (Plate VIII. 

 Fig. 26.) shows each of these external plates to be the closed 

 termination of a short tube, that has in the transverse section 

 a hexagonal form. These tubes are filled in with a darker material, 

 which, unfortunately, is without structure, and any determination 

 of the af&nities of the fossil must depend entirely on the external 

 form, and the arrangement of the parts. Of necessity, these are 

 defective and unsatisfactory materials ; nevertheless, the fossil seems 

 to me to present so remarkable an appearance, and so close an 

 approximation to a portion of the inflorescence of an Aroideous 

 plant, that I do not hesitate to refer it to this family ; and I enter- 

 tain the hope that one result of this notice and the accompanying 

 figure may be to draw some attention to the fossil, which seems to 

 be by no means rare, and so supply the means for more completely 

 establishing its af&nities. 



The AroidecB are monocotyledonous plants, with numerous naked 

 flowers on a solitary spadix. The female flowers are at the base of 

 the spadix, and the male above, sometimes separated by a series of 

 neuter organs from the female, and often surmounted by a free 

 flowerless termination of the spadix. The plants of the family are 

 chiefly natives of the tropical and warmer parts of the earth, many 

 of them being arborescent and of considerable size, clinging to 

 trees by means of aerial roots which they freely send out. The 

 majority of these large tropical species have the cells of the 

 anthers buried in the substance of a very thick connective, and the 

 apices of the stamens forming peltate shields which cover either the 

 whole of the spadix above the female organs, as in one large tribe, 

 or only a portion of it, leaving a naked appendage beyond the flowers, 

 as in the other section. 



On the plate (Plate VIII. Fig. 3) we have figured a spadix of 

 a species of Xanthosoma, the lower portion of which is covered 

 with the pistils, the middle by the neuter organs or imperfect 

 stamens, and the upper by the true stamens. A comparison of the 

 fossil with the recent plant will show how remarkably they agree. 

 The axis of the spadix of Xanthosoma, in growing, becomes hollow, 



