Dr. T. Taylor on five new species of Cryptogamic Plants. 381 



Plagiochila, Nees et Mont, 



1. P. sub-bidentata (Tayl.) ; caule repente laxe caespitoso, surculis 

 decumbentibus subflexuosis, foliis basi imbricatis erecto-patenti- 

 bus margine ventrali basi gibboso oblique ovatis acutis apice sub- 

 biciliatis, calyce oblongo ore oblique subtruncato dentato. 



On Scklotheimia cirrosa (Hook.), Jamaica. Dr. J. M'Nab. 



Shoots one or two inches long, scarcely one line wide, brown, 

 attenuated above. Perigonial spikes one or two in the course of 

 the shoots. Perichsetial leaves upright, adpressed to the base of 

 the calyx ; this has a marginate angle on the upper side, and the 

 mouth roundly truncate and split on one side. Pedicel just ex- 

 posing the capsule out of the calyx. This differs from P. abrupt a 

 (Lindl.)by the procumbent shoots, which are longer and more 

 attenuated above ; by the wider bases of the leaves, which at the 

 ventral margin form a crest below the stem ; by the teeth of the 

 leaves being so slender as to be mere cilia, and by the minuter 

 cells of the leaves. 



Parmelia, Ach. 



1. P. ochroleuca (Tayl.); thallo laciniato-lobato, lobulis ultimi s 

 brevibus sinuato-divaricatis praemorsis retusisve albo-cinereo ma- 

 dore immutato tenuissime albo-reticulato subtus albido-fibrilloso, 

 apotheciis submarginalibus concavis margine incurvo demum gem- 

 mis planis subrotundis coronato, disco castaneo subtus nudo. 



Port Royal, Jamaica. Dr. J. M'Nab. 



Thallus three to four inches wide, when dry waved on the 

 surface ; sinus of the lobes oblong : margin brownish ; surface 

 pale ash-coloured, whiter beneath, where the pale fibrils resemble 

 those of a Peltidea. Disc of the apothecia concave when dry, 

 flat or slightly convex when moistened and then assuming a 

 lighter colour. The disc is naked beneath, that is, it is destitute 

 of a thallodal layer, hence the apothecia seen by transmitted 

 light are pellucid in the centre. Allied to Sticta Leylandii (Tayl.), 

 which however differs by the upper surface being covered with 

 closely set clusters of buds, by the smaller size and darker colour, 

 by the shorter fibrils beneath the thallus, and by the apothecia re- 

 ceiving at length a short podetium from the thallus. The genus 

 Sticta seems scarcely separable by a decisive character from Par- 

 melia, and this again in another direction passes into Lecanora. 



