101 
X. Contributions to the Lichenogr aphia of New Zealand ; being an account jecith figures, of 
some new species of G-raphideae and allied Lichens. /By Chas. Knight, Esq., F.L.S . 
Auditor- General of New Zealand ; and W. Mitten, Esq., A.L.H. 
Read April 19th, 1860. 
1 HE following enumeration of the species of Graphidea?, additional to the Flora of N e\v 
Zealand, includes some very curious tropical forms, as well as a proposed new genus for 
the reception of two nearly allied Lichens which do not appear to correspond with any of 
the numerous genera with which this group seems overburdened. Great difficulty, how- 
ever, attends the investigation of these obscure plants ; and much more seems yet required 
to be known of the tropical forms, before the genera, as at present constituted, can be 
considered as more than arbitrary divisions. 
Opegrapha, Ach 
0. varia, Pers. 
Hab. On trees, Auckland. 
The following forms have been observed : 
1. Thallus olive-brown ; apothecia superficial, slender ; rima a mere chink ; spores 5-9- sep- 
tate, measuring from 0*0003 to 0*00115 of an inch. 
Pl. XI. fig. 15. a. sections of the apothecium ; b. thecae • c. spores. 
2. Thallus olive-brown tending to grey ; apothecia more or less immersed when moist, 
the margin separating in the middle ; spores 4-5-septate, measuring from 0*00024 to 
0*0009 of an inch. 
Pl. XI. fig. 16. a. section of thallus and apothecium; b. theca; c. spores. 
3. Thallus dusky-grey ; apothecia immersed when moistened, oblong, open ; spores 3-4- 
septate, measuring from 0*00025 to 0*0007 of an inch. 
Pl. XI. fig. 17. a . section of thallus and apothecium; b. spores. 
The form 2 closely resembles the O. varia ysly. tridens, Schaer. Lich. Hclv. Exsic. So. 98. 
In all essential particulars the New Zealand forms agree with the European. 
O. cinerea, Knight & Mitten. Thallus ashy-grey, pulverulent, sometimes obsolete ; apo- 
thecia superficial, simple, oblong, straight or curved, closed ; spores brown, 3-septate, 
sometimes 1-septate, and then contracted in the middle, frequently mural, measuring 
from 0*00025 to 0*00075 of an inch. 
Hab 
The short thick closed apothecia readily distinguish this species from the preceding. 
Pl. XL fig. 18. a. sections of apothecia ; b. thecae ; c. spores, in which the different degrees of septation 
are seen* 
