The Present Position of Palaeozoic Botany. 183 



tlie group which I have termed the Primofilices, of which the Botryo- 

 pterideae are the best-known famih' at present." Prof. Lig-nier, in 

 1903, laid great stress on the existence, in early Palaeozoic times, of 

 an ancient group of Ferns, of which the Botryopterideae were among 

 the derivatives, retaining some of the primitive characters. There 

 is thus a considerable consensus of opinion as to the important posi- 

 tion of this family in relation to the evolution of Ferns. Mr. Arber 

 has done good service in pointing out that the particular group which 

 we call Botryopteridae is only to be regarded as one family of a 

 race presumably far more extensive. 



Miss Stopes, in her interesting paper, just published, on TîibicauJis 

 Sutdiffii, raises the question '"whether the Botryopterideae are really 

 members of the Primofllices in the true sense of the word." Her 

 reason for doubting the primitive nature of the family is the fact 

 that they often possess tracheides with multiseriate bordered pits, 

 a very constant character of Pteridosperms and the earlier Gymno- 

 sperms. In the Botryopterideae they appear to have been less con- 

 stant; Renault, for example, found tracheides of this kind in Zijgo- 

 pteris Lacattii (petiole) while in the closelj^ allied Z. hibradensis o\\\j 

 scalariform tracheides were present. Pitted tracheides of the Gymno- 

 spermous type occur, as Miss Stopes herself points out, in the Ophio- 

 glossaceae; their presence in Botryopterideae seems to me just what 

 we should expect in an early synthetic group, with affinities in various 

 directions. The relation of this famil}'. or rather of the Primofllices 

 in general, to the Pteridosperms is an important question to which 

 we shall return below. 



Other Primofllices. 



I may now shortly refer to one or two forms, showing fructifi- 

 cation, the relation of which to Botryopterideae is uncertain, while 

 we may safelj^ assign them provisionally to the wider group which 

 Mr, Arber names Primofllices. Petrified sporangia, apparently of 

 Ferns, are fairly common in the calcareous nodules of the English 

 Lower Coal-Measures, and also in the calcified material from the 

 Lower Carboniferous of Burntisland in Scotland. I have recently paid 

 considerable attention to these fossils and have been able to distin- 

 guish several well-marked types. Some of these can be referred with 

 certainty or probability to known plants, namely Staiiropicris oJdhamia, 

 Botryopteris and Zijgopteris. In other cases no suck attribution is as 

 yet possible. It is convenient to have a name for these unassigned 

 Fern-sporangia, and I propose to use the generic designation Pterido- 

 theca, to include petrified sporangia, of Palaeozoic age, possessing an 

 annulus or other characters indicating Filicinean affinity. 



