126 Rev. W. A. Leighton on the Oenus E-amalina. 



ft Medulla K - . 

 53. R. cuspidata (Acli.) and its vars. crassa (Del.) and 

 suhvittata^ Njl. 54. R. vittata, Nyl. 55. R. t'uuji- 

 tana.j Salzm. 5Q. R. incequalis^ Nyl. 



5. Stirps R. pusiUce. Thallus smooth or nearly so, fistulose, 

 here and there perforated. Medulla K - (except in 

 R. suhpusilla^ which has a yellow reaction). 



A. Cortical layer amorplious. 



57. R. pusiUa, Le Pr^v. 



B, Cortical layer filamentose. 



a. Spores straight. 



58. R. tasmaju'ca, Nyl. 59. R. inflafa, Hook. fil. & 

 Tayl. 60. R. geniculata^ Hook. & Tayl. ; *^. suh- 

 2nisiUa, Nyl. 61. R. mmuscula (Nyl.) and its vars. 

 poUinariella, Nyl., and dendroidella, Nyl. ; *R. tnter- 

 medictj Dei. Q2. R. jJumila^Mnt.; *R.javanica,l^yl. 

 63. R. suhgem'cidata, Nyl. 64. R. Panizzei, J). N. 



b. Spores curved. 



65. R. abyssinica^ Nyl. 



[Those marked * are subspecies.] 



From the above we find that our British species must be 

 rearranged thus : — 



1. R. tlirausta (Ach.). Pale straw-colour, Jilif or mi-terete 

 or subterete, here and there compressed, somewhat shining, 

 very slenderly divided and excessively branched^ capillari- 

 attenuate and interwoven at the apices ; cortical layer filamen- 

 tose ; medulla K — ; apothecia unknown. 



On subalpine rocks, rare. 



Syn. Alectoria thrausta, Ach. L. U. 596, Syn. 294. R. 

 thrausta, Nyl. Mon. Ramal. 18 ; Leight. Lich. Fl. G. B. 94. 



Exs. Fries, L. S. 267. 



Geog. distrib. Europe. 



England. Longmynd!, Shropshire. 



Scotland. Coast of Kincardineshire ; Morrone ; Braemar ; 

 Craig TuUoch, Rev. J. M. Cromhie. 



Cliannel Islands. The Warrens, Noirmont, Jersey !, Mr. 

 Larhalestier. 



2. R. calicaris (Hffm.). Pale glaucous-grey, albescent, or 

 albido-flavescent, rigescent, erect, dichotomously branched ; 

 lacinice linear ^ compressed^ elongatedj attenuated at the apices^ 

 longitudinaUy lacunoso-canaliculate j cortical lay er filamentose j 

 medulla K — ; apothecia terminal^ subtended by the dejlexed 



