LEPTOGIUM. 165 



lead-coloured and coerulescent ; lobes irregularly rounded and 

 more entire, or sinuate-laciniate and sub-crenate, the margins 

 more or less ascendant and plicate-undulate; apothecia mid- 

 dling to ample, elevated, zeorine ; the red disk bordered by a 

 paler margin, which is inclosed by a finally leafy thalline one. 

 Spores acuate-ovoid, sub-muriform (transverse series of spore- 

 cells 4-6), decolorate, ^^ mic. Collema, Ach. Lick. p. 655. 



Mont, in Ann. Sci. 1841,^. 74. 



a. vesiculosum ; apothecia terminating bladdery podetia, 

 which are now drawn together above into plaited coronals en- 

 circling the fruit. Collema bullatum, Sw. Lich. Amer. t. 16. 



Leptogium, Nyl. Syn. 1, p. 129. 



b. phyllocarpum ; apothecia less or at length scarcely ele- 

 vated ; the thalline margin from simply plicate becoming densely 

 leafy and crisped, and the whole fruit at length large. Col- 

 lema phyllocarpum, Pers. Nyl. Syn. I. p. 130. 



Trunks, a, Mexico, Nylander I. c. 1858. b, Texas, Wright. 



Florida, Austin. Mexico, Nylander. L. Javanicum, Mont. 



(L. sphinctrinum, Nyl.), to judge by my specimens from Herb. 

 Junghuhn ( V. d. Bosch), is hardly separable from b ; and L. bul- 

 latum, Mont. & V. d. B., from the same herbarium, is possibly 

 too near the same ; and sufficiently illustrates Montagne's earlier 

 judgment, which is accepted above. The species is also most 

 closely akin to L. chloromelum -, and it is difficult to see why 

 one of the two specimens called L. phyllocarpum in (my copy of) 

 Lindig Herb. N. Gran. n. 1660, should not pass equally well for 

 the lichen first-named. 



20. L. Burgessii (Lightf.) Mont.; thallus ample, loosely ag- 

 gregate, laciniate-lobate ; from glaucous-greenish and lead-col- 

 oured passing into purplish-brown ; the imbricate lobes rounded, 

 sinuate, from smoothish becoming granulate, and beset at length 

 densely with finger-shaped lobules, cristate-lacerate ; beneath 

 ash-coloured, and more or less delicately downy ; apothecia sub- 

 sessile but appearing depressed, middling-sized to ample, flat- 

 tish, zeorine ; the dark-brown disk bordered by a paler margin, 

 which is crowned with a densely leafy and crisped thalline one. 

 Spores ellipsoid, apiculate, muriform-multilocular, decolorate, 



^ mic. Collema, Ach. L. U. p. 645. Leptogium, Mont. 



Canar. p. 129. 



Trunks, White Mountains, fertile, Tuckerman Gen. 1872. 





