362 INDEX. 



Parmelia sorediata, Tuckerm., 227. 



speciosa, Ach., 225. , 



stellaris, Wallr., 225. 



straminea, Wahl., 229. 



stygia, Ach., 221. 



subfusca, Fr., 231. 



tartarea, Ach., 231. 



terebrata, Mart., 220. 



tiliacea, Ach., 218. 



triptophylla, Fr., 228. 



varia, Fr., 233. 



ventosa, Ach,, 233. 



verrucosa, Ach., 234. 



vitellina, Ach., 234. 

 Parmeliaceae, Fr., 197. 

 Parmeliese, Eschw., 197. 

 Patellaria, Fr., 2-17, 230. 

 Patellatae, 261. 



Peikce, Benjamin. On De Vice's fourth comet, 39. On Wartman's 

 supposed planet, 41. On the planet Neptune, 57, 65, 185, 285. 

 On perturbations of Uranus, 144. Formulse for the perturbations 

 of Neptune's longitude and radius vector, 286. Neptune's satellite, 

 295. Investigations into the action of Neptune upon Uranus, 332. 

 On the discrepancies between the predicted and observed orbits of 

 the planet which disturbs the motions of Uranus, 338. 

 Peltigera, gen., Hoffm., 197, 211. 



aphthosa, Hoffm., 211. 



canina, Hoffm., 211. 



horizontalis, Hoffm., 212. 



malacea, Ach., 211. 



polydactyla, Hoffm., 212. 



rufescens, Hoffm., 211. 



venosa, Hoffm., 212. 

 Pertusaria, gen., DC, 199, 276. 



faginea, L., 277. 



globularis, Ach., 277. 



hymenia, Turn., 277. 



papillata, Ach., 277. 



pertusa, Ach., 276. 



