Dr James Stirton on Lichens. 361 



so-called hypothallus, which is said by several writers to 

 be distinctive of the genus Pyxine^ would seem at first siglit 

 to forbid association in this direction, but an exaujination 

 of a considerable number of specimens of Pyxinc from 

 tropical and sub-tropical countries scarcely warrants the 

 presence of a hypothallus as a generic character.* The 

 fact that no species of the genus Pyxine is European can 

 scarcely be said to form an obstacle to association of the 

 present lichen with it, and the rather that our knowledge 

 of the distribution and range of lichens is still very 

 defective. 



In the absence of other authentic specimens, either 

 British or European, I hesitate to classify this plant under 

 Pyxine although I confess to a bias in this direction. 

 Accordingly I shall, meanwhile at least, rank it alongside 

 Lecidea canescens under the name Lecidea eruhescens. 

 Another curious analogy between this lichen and Pyxine 

 coccifera is to be found in the identity of the chemical 

 reactions as detailed below. 



Lecidea. 

 Thallus pallidus vel pallide glaucescens, adpressus, anguste 

 radiato-laciniatus, laciniis coatiguis et hinc inde pallide lutescenti- 

 sorediosis, intus rubescens, subtus erythrinosus vel coccineus. 

 Hypothallus nigricans passim visibilis, eradiculosus. Apothecia 

 sessilia nigra plana marginata ; sporse (4-8) nae fuscae, ellipsoideae vel 

 fusiformi-ellipsoideae, 2-loculares, vix septatae, interdum. fere polari- 

 biloculares, raro simpHces, -013 - '02 x -006 - -008 mm.; paraphyses 

 graciles irregulares nigro-clavatae ; hypothecium fuscum vel fusco- 

 nigrum. lodo gel. hym. cserulescens dein sordida. Medulla praeser- 

 tim infra, K sordide purpurascens. 



Since writing the above Dr Pinkerton has died, at the 

 early age of 32. He did much in the interests of his 

 profession while serving under the Turkish flag during the 

 late Turco-Eussian war, and gave abundant promise of 

 more. There are good grounds for believing that the 

 exposure and irregular mode of living had much to do in 

 determining the fatal result. While he kept himself well 



* The majority of specimens of Py.rme growing on bark show traces of this 

 structure, while in one specimen from India on stones scarce!}' any can be 

 detected, and radicles are consequently absent. 



