830 Charles Paul Alexander 



The Canadian-Transition zone. — A great many species occur in both 

 the Canadian and the Transition Ufe zone, and these for the most part 

 find their northern or southern hmit in one or the other of these belts. 

 The floral constituents of this border zone are numerous and varied, 

 a large number of the Canadian forms finding their southern limit in 

 the Transition zone, and, conversely, many of the more southern species 

 extending their range into, and finding their northern limit in favoral)le 

 situations in, the Canadian zone. The more notable plants that seem to 

 fall within this category are: 



Maianlhemum canadeiise Desf. Rvbus hispidus L. 



Streptopus roseus Alichx. Sanguisorba canadensis L. 



Medeola virginiana L. Nemopanthus mucronata (L.) Trel. 



Cypripedium arietinum R. Br. Acer pennsylvanicum L. 



hirsutum Mill. Hypericum canadense L. 



Habenaria lacera (Michx.) R. Br Trientalis americana (Pers.) Pursh 



Laportea canadensis (L.) Gaud. Gentiana linearis Froel. 



Arceulhobium pusillum Peck Diervilla Lonicera Mill. 



Asarutn canadense L. Viburnum cassinoides L. 



Polygonum amphibium L. Lobelia Kalmii L. 



Caltha palustris L. Solidago latifolia L. 

 Actaea alba (L.) Mill. rugosa Mill. 



CaulophyUum ihaliciroides (L.) Michx. graminifolia (L.) Salisb. 



Corydalis sempervirens (L.) Pers. Aster umbellalus Mill. 



Pyrus arbutifolia (L.) L. f. Anaphalis margaritacea (L.) B. & H. 



melanocarpa (Michx.) Willd. Erechtites hieracifolia (L.) Raf. 

 Potentilla palustris (L.) Scop. 



The- majority of the crane-flies of the northeastern United States seem 

 to belong here. There are many species which are strongly Canadian 

 in their associations but still seem to range outside the Canadian zone. 

 In the following Ust these species are designated by the letter C, in paren- 

 thesis. It must be understood that many of these species are about as 

 typically Canadian as those given in the preceding list, but slight extensions 

 of their range make it appear more desirable to include them in this quali- 

 fied list. 



The few species which are Transitional but range into the Canadian 

 zone are here designated by the letter T. 



Protoplasa fitchii O. S. Dicranomyia macateei Alex. (C) 

 Trichocera subsinuata Alex. (C) monticola (Alex.) (C) 



Rhyphus alternatus Say morioides O. S. 



Dicranomyia gladiator O. S. (C) pubipennis O. S. (C) 



globithorax O. S. (C) pudica O. S. 



haeretica O. S. Limnobia triocellata O. S. 



immodesta O. S. Rhipidia fidelis O. S. 



