4 I 



CONCLUSION 



To judge from the foregoing study of PalUvicinia. P. ZolUn^. 

 some respects more like M or la a thin it U like the other fpecie* of Palla- 

 it were examined. 'I :c of the thalluv which has a broad. 



indefinite milnt>. merging gradual! e wings, instead of the sharply 



defined midrib, and thin \vmgx <f Eupallavicinia* The conducting *frtfff, 

 howt The sporophyte. also, approaches in form 



that - these difference*. comUned with the very dU- 



ire sufficient to warrant the retention of the generic 

 Mitt< < n.lroid species of Pallavicinta, may be questione 



<>n t! we are inclim-. I t<> think : -lifted and the members of 



the section Eupallavicinia might properly be transferred to Blyttia. 



The inter-relationships of the Jungermanniales are very |Mi|J< linfl 

 Cavers (2) in his recent excellent summary of the subject points oat that 

 there .ally no constant point of difference between the two families 



accae and Aneuraceae (Schiffner's families Metigerioideae and 

 Leptotheceac). Cavers places in the 6rst family the genera Blyttia ( Pal- 

 i, Symphyogyna and Makinoa. In the latter are also 

 included four genera, Aneura, Metzgeria, Umbraculum and 

 The two latter are often united into a single genus. H; 

 they are abundantly distinct and probably not closely related. Umbracu- 

 lum is undoubtedly related to Metzgeria, but Podomitrmm. except for 

 the position of the reproductive organs, is hardly distinguishable from 

 Blyttia. cither in the structure of the thallus or that of the 

 /'. nmlacccnsf. for example, a species common in Western 



absolutely in-' liable from a typical Blyttia. except for the poaittoo 



of the reproductive organs upon short ventral branches, instead of upon 

 the ordinary shoots. We believe that Podomitnum should be placed in 

 the Blyttiaceae, rather than in the Aneuraceae, mrT^ffpg it seems best 

 to retain these two families, and not unite them into a single one as Cavers 



The production of the reproductive organs upon special 

 which appears to be the only constant difference between the / 

 ami I'.Mtiaceae. seems hardly of sufficient importance to warrant the 

 establishment of two families, especially as. except for the small site of 

 the fertile branches, they do not differ essentially from the ordinary shoots 

 upon which the reproductive organs occur in the Blyl 



