WiEGANu : A Revision of the Genus Listera 161 



Don for an orchid of India. As a substitute for this name Z. 

 Smallii has been employed in this paper. One of the most inter- 

 esting facts encountered in the study was the discovery of this 

 species again in eastern Asia. The two regions are as widely 

 separated as can well be imagined, still it will be seen that we 

 have here only an illustration, and a very fine one, of Dr. Gra}''s 

 observation regarding the relation of the floras of eastern i\sia and 

 eastern North America. 



The last of the series of American forms to be described was 

 L. caurbia which Piper recently separated from the Z. conval- 

 larioides as found on tlic Pacific coast. 



Another American species is here recognized for the first time, 

 and has been given the name Z. auricidata. Onl}' a {^\\ specimens 

 have been seen and these were from a very restricted locality. 

 It may be said to be peculiar to the mountainous regions of 

 northern New Hampshire and Maine, but is closel)' related to the 

 Z. borealis of the Rocky Mountains. 



Of the five species from Eastern Asia, three were described by 

 Lindley, viz., L. pbictoruui^ Z. tenuis and Z. inicrajitha^ of which 

 the second seems scarcely distinct from the first. Z. piiberida of 

 Maximowicz is an elegant species from China and now reported 

 also from Japan. Z. Japonica, also of Japan, was first described by 

 Blume and well figured in his Orchid. Japon. 



Regarding tlic relationship and ph^dogeny of the species little 

 need be said. The usual difficulty was encountered in arranging 

 them in a lineal series, although perhaps in a more marked degree 

 than is usual ; consequently a few words of explanation ma}' be 

 necessary to express more clearly the writer's \'iews. It seems 

 probable that the imbifurcatcd lip and basal leaxes of Z. uncrantJia 

 represent a primitive condition and perhaps a transition to other 



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genera. Then starting with Z. inicrantha and Z. Japonica as repre- 

 senting the more primitiv^e type, two divergent lines of develop- 

 ment may be traced. Through Z. australis we pass to Z. ovata^ 

 Z. aiiriculata and Z. horealis^ all with oblong lips and without 

 basal teeth. From forms represented by Z. cordata^ although the 

 transition is not quite so clear, have descended through a type 

 similar to Z. SviaUu the reniform-leaved species, Z. pubcrnla and 

 Z. piiictonun ;' Txwdi also from the type of Z. Sinallii along another 

 line of development, Z. caurina and Z. convaUarioidts. 



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