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HIV . — Observations on New Lichenicolous Micro-Fungi. By W. Lauder Lindsay, 

 M.D., F.L.S., &c. (Plates XXIII.-XXIV.) 



(Read 19th April 1869.) 



In the course of my studies on the Microscopic Anatomy of Lichens, during 

 the last fifteen years, I have frequently met with various more or less minute 

 Parasites — mostly black and punctiform or papillseform — sometimes disciform or 

 maculseform — affecting either the thallus or apothecia of lichens, or both thallus 

 and apothecia. They grow equally on foliaceous and crustaceous lichens, 

 especially of the following genera : — Parmelia; Physcia; Umbilicaria; Solorina; 

 Peltidea ; Nephromium; Sticta ; Stereocaulon ; Usnea ; Neuropogon; Cladonia; 

 Bceomyces ; Squamaria ; Placodium ; Lecanora ; Pertusaria ; Thelotrema ; 

 Lecidea; Gr aphis ; Endocarpon ; Verrucaria. 



Most of these Parasites occur on lichens in my own Plerbarium, collected by 

 myself in 1856 ; or on lichens sent me for examination and determination by 

 various British lichenologists between 1856 and 1858. They were examined, and 

 described with figures in my Herbarium Note-books, between 1856 and 1859; 

 in most cases without the assignation of names. I have not hitherto published 

 their descriptions, or assigned names, for a variety of reasons, and especially on 

 account of the difficulties which appear to me* to surround the determination 

 of what, to any single observer, seem to be (so-called) "new species." Hence the 

 parasites in question have been accumulating in my Herbarium, and their descrip- 

 tions in my Note-books, for twelve years or upwards ; and they now form a large 

 and interesting, though obscure and puzzling, group of microscopic plants. I 

 cannot, however, quote them in a Memoir I have in preparation on the Spermo- 

 gonia and Pycnidia of the lower lichens (with which Spermogonia and Pycnidia 

 the said parasites are frequently apt to be confounded) without placing their 

 description — and, in certain cases at least, their names — on record in a form con- 

 venient for future reference. Nor can I otherwise contrast with them various 

 groups of Lichenicolous Micro-Lichens,f Micro-Fungi, or Micro- Algse, which have 

 been described by other authors, or having been observed are yet to be described by 

 myself Inasmuch, moreover, as the said descriptions and names have not been, 

 so far as I am aware, published by other authors — whether fungologists or 



* Vide Author's " Contributions to New Zealand Botany," 1868, p. 22 ; " Otago Lichens and 

 Fungi," Transactions of Royal Society of Edinburgh, vol. xxiv. p. 407; "Parasitic (lichenicolous) Micro- 

 Lichens," Quart. Jour, of Micro. Science, January 1869 ; " Polymorphism in Fructification of 

 Lichens," Quart. Jour, of Mici'o. Science, January 1868. 



\ E.g. " Enumeration of Micro-Lichens parasitic on other Lichens," Quart Jour, of Micro. 

 Science, January 1869. 



VUL. XXV. PART H. 6 R 



