Affinities of the Genus Pothocites. 29 



belonged to an extinct species of the genus Pofhos, or to 

 some extinct genus of i)lants very closely allied to it," was 

 at the time supported by Mr M'Nab of the Botanic Garden, 

 Dr Greville, and many other gentlemen. 



Professor Henslow, who also examined the specimen, 

 thought it was probably related to rotamogeton or Pothos. 

 He conceived that the spadix was continuous and not 

 jointed, the apparent joints being the result of compression. 

 He could not see any evidence of ribs, and was " unable to 

 determine the exact nature of the quadrifarious arrange- 

 ment, whether the parts are calyx-scales, or seed-valves." * 



I believe Dr Paterson has been deceived in some points 

 by certain appearances in his fossil. 



This view as to the affinity of Pothocites has been ac- 

 cepted by Mr Carruthers, Professor Balfour, and others, f 



Professor Williamson, however, has expressed some doubt 

 as to the systematic position of the plant. In a lecture on 

 " Primaeval Vegetation in relation to Natural Selection and 

 Evolution," he says — " It is also necessary to state further 

 that the Coal-measures reveal some other remarkable stems, 

 the exact relations of which are not yet fully ascertained." 

 Then in a footnote he adds, — " This is especially in reference 

 to the Lyginodendra, Noeggcrathice, and to the curious 

 Pothocites Grcmtonii, which latter is supposed by some 

 botanists to be a monocotyledonous Angiosperm ; this, 

 however, appears doubtful. The genus Antholithes, from 

 the Coal-measures, was regarded as a dicotyledonous An- 

 giosperm allied to Orobanche ; but this idea is now aban- 

 doned, and the plant is now referred to the group of Gymno- 

 spermous exogens. I expect that further research will 

 lead to some similar change in regard to Pothocites." | 



From a detailed examination of five specimens of Potho- 

 cites § it is shown that the plant possessed a segmented fruc- 

 tifying spike or cone. In tlie only perfect specimen the 



* Loc. cit., p. 52, note. 



t Carruthers, '•On Fossil Plants," delivered to the Geologists' Association 

 as Presidential Address, Nov. 5, 1875; "The Testimony of Fossil Botany in 

 reference to the Doctrine of Evolution," Presidential Address, delivered to the 

 Geologists' Association, Nov. 3, 187"; "Notes on some Fossil Plants," GeoL 

 Mng., vol. ix., 1872 ; Balfour, Introduction to tlic Stmly of Palmontological 

 Botany, p. 66 (Edin. 1872) ; Geikie, Text- Book of Geology, p. 732 (1882). 



X W. C. Williamson, Essays and Addresses by Professors and Lecttcrers of 

 Oivens College, Manchester, p. 229, Macmillan, 1874. 



§ Vide Plates I.-IV., Explanation, p. 37. 



