374 T. (J. HALLE. [Nov. 1913. 



Pachypti r'is. And as Fachi/pteris is the older name and has 

 been commonly used — also by Professor Seavard in the 'York- 

 shire Flora' — the name Dicliopteris should be rejected. The 

 only ])lan to retain the genus Bichopicris is evidently to em- 

 plo}' it in a very restricted sense for forms like those from 

 the Italian Oolite, in which case my species of ScJerojyteris 

 naturally cannot be included in it. Whether the venation 

 and the peculiar habit of the Italian forms are sufficiently 

 important characters to warrant this course, will not be dis- 

 cussed here, but it is certain that if Dicliopteris is used 

 in the sense of Prof. Seward's ^ it cannot be upheld but must 

 be rejected in favour of Facliyptcris. Whichever course be 

 followed, therefore. Dichopjfrris has only a secondary impor- 

 tance for the delimitation of the genera Pachypteris, Tlmui- 

 feldia and Sclcropteris. This is the reason why I did not consider 

 it in the discussion of these genera, judging it wiser to leave 

 this question to somebody who could make a thorough compara- 

 tive study of the Italian forms. — From what has been said above 

 regarding the relation of Pachyptteris and Dichopteris, it will 

 already be clear why P. dalmatica, which was probably cor- 

 rectly^ referred by v. Kerner to Pachypteris^ has not been in- 

 cluded in Dichopfcris. 



The nomenclature of Zamitean fronds, on which Professor 

 Seward also remarks, is a very difficult matter, and as yet 

 there hardly exists any method of classification which is not 

 beset by difficulties. In my Grraham Land paper I have dis- 

 cussed the relations of the genera ZamiUs. Ptilopliyllum, and 

 Otozamites: and Professor Seward remarks that I have used 

 Zamites 'for several forms which agree much more closely 

 with Ptilophyllnm fronds than with Zamites as usually em- 

 ployed'. This remark is interesting as it shows that Profes-j 

 sor Seward accepts the generic name Ptilophyllam. If both' 

 Zamites and Ptilopliylluni are employed it is naturally neces- 

 sary to establish some agreement as to how the genera are 



* Fossil Plants. Vol. 2, p. 552. 



