PITIIOEA. 213 



tunica arachnoidea was very conspicuous, 

 filled with innumerable vessels, and of such 

 firmness as to be very easily separable from 

 the cornea. In the middle, near the optic 

 nerve, it looked red from the number of 

 blood-vessels, but the sides were of a 

 blueish black. There were two orifices at 

 the larger corner of the eye. 



On this same mountain grew in abun- 

 dance a kind of Musens lichenoides of a 

 greyish black colour, as if scorched or 

 burnt, different from what authors have 

 described, being more coriaceous and 

 greenish, while that is black and brittle, 

 almost like burnt paper, and smooth un- 

 derneath ; whereas the plant I here ob- 

 served has the under side entirely covered 

 with fibres like little roots. (This was the 

 true Lichen velleus] of Linnaeus, preserved 

 in his herbarium, and figured in Dillenius, 

 tab, 82./. 5. See FL Lapp. ed. 2. 360.) 



The branches of Spruce Fir here began 

 to show that appearance to which Clusius, 

 if my memory does not deceive me, has 



