436 DE LAUDER LINDSAY ON THE 



that certain apothecia, spermogones, or pycnides, which usually or always occur 

 by themselves, unassociated with their complementary forms of fructification, are 

 really properly referable to plants even of a different order or family. In the 

 absence of spores, it is generally impossible or unsafe to determine either species 

 or genus ; but their presence does not always render diagnosis facile — for num- 

 bers of plants presently classed in the genus Microthelia possess essentially the 

 same small, brown, solseform, 1-septate spores, while their habitats or other 

 characters are diverse. 



There are several parasites on Otago Lichens, which I prefer, for the reasons 

 above assigned, to describe in a group as Fungo-Lichenes, rather than either as 

 Lichens or Fungi.* In my Dunedin Herbarium, some of these exhibit only 

 perithecia (Microthelia) ; others only spermogones (Phymatopsis) ; while a few 

 occur only as sterile maculae or warts, which are presumably rudimentary or 

 degenerate perithecia or apothecia, or confluent clusters thereof (Celidium). In 

 the two latter classes of cases my New Zealand specimens do not in themselves 

 furnish sufficient means or characters for their determination. But on the same 

 or similar Lichens from other parts of the world, I have found what seem to be 

 links connecting the maculae or spermogones in question with the relative 

 apothecia, and which enable me — though doubtfully, and with reservation after 

 the explanation already given — to refer them to apparently new forms of Celidium 

 and Phymatopsis. The nature and relations of these Otago parasites cannot, 

 however, possibly be understood (in so far, at least, as they are imperfect or 

 infertile) without reference to the fertile condition of the most closely allied 

 European plants; and I have the less hesitation in here recording the results 

 of a comparative examination of the latter, that they themselves are little known 

 to Lichenologists and Fungologists, and hence possess an inherent interest war- 

 ranting their description. 



Genus I. llicrothelia, Korb. Syst. Licb. Germ. 372 (Syn. Verrucaria, Pers. ; Pyrenula, Ach. ; 

 Endococcus, Nyl. ; Tichothecium, Mass. ; Phoeospora, Hepp ; Buellia, De Not. ; Lecidea, 

 Ach. ; Abrothallus, De Not. (Lichens), pr. p. : Sphceria, Hall (Fungi), pr. p. 



Typical species have papillaeform, superficial perithecia : whence the generic 

 name (fuicpos, small, and OqXy, a wart or papilla) . In recedent or exceptional forms, 

 the perithecia are punctiform and immersed, or semi-immersed. In all cases the 

 perithecia are extremely minute or microscopic ; and they resemble in size and 

 external aspect the black papillaaform or punctiform spermogones of many 



* In the Society's " Proceedings," vol. v. p. 528, 1 have classed them provisionally as Sphcerice, 

 to which they have a more or less resemblance, and to which some at least may hereafter really 

 prove to be referable. Nos. 4, 5, 7, and 8 are now described as Microthelice ; No. 6 as a Phymatopsis ; 

 and No. 9 as a Celidium. 



