318 Howe: 



GENUS 



dian zone, and occurs also in northern Maine, its range being quite 

 similar to that of U. longissima. On what grounds Willey included 

 it in his New Bedford list, we cannot tell, as the entry is again 

 without annotation. "*" There are, however almost Hudsonian 

 "islands" within his area where it could occur, with such species 

 as Certhia familiaris americana (Bonap.) and Parus \Penthest€s\ 

 Jiudsonicus Forst. Transitional forms between this and the typical 

 barbata are common to the Transition regions. 



USNEA BARBATA PLICATA Fr. 



This subspecies is identical with the last, in regard to slender- 

 ness of filamentation, length of thallus, color and scarcity of 

 apothecia. The difference lies in the lack of numerous rectangu- 

 larly arranged fibrils. A specimen determined by Tuckerman f 

 is unlike most of the specimens of recent collection and determi- 

 nation in the herbaria I have examined, and absolutely accords 

 with the diagnosis. Under this subspecies I have found much 

 material of expert determination which in reality is the epapillate 

 U. trichodca. The range oi plicata is held to be, so far as I can as- 

 certain, coextensive with the last subspecies, though this form is 

 evidently much less common and is more northern, being exhibited 

 typically only from Alaska, northern Canada, and Siberia. I have 



not as yet seen an absolutely typical example from the New Eng- 

 land states. 



USXEA BARBATA ARTICULATA Ach. 



This subspecies does not occur in this region, as Tuckerman 

 Implies, or else it is generally overlooked by collectors. 



Ach 



This species in the majority of cases is well marked and easily 

 distinguished. The angular, generally epapillate thallus some- 

 times attains a length of over one meter. Occasionally a specimen 

 shows but little angulation, being nodulose instead, and approaches 

 barbata or one of its subspecies (see specimen In SuU. Moss. Chapt. 



Will 



seated by typical specimens. 



t In the Taylor Herbarium, Bost. Soc. of Nat. Hist., from British North America ; 

 one fibril figured in our plate 22. 



