Mr. F. Walker's Descriptions of Aphides. 269 



were now in flower at this place, but I saw nothing else of any 

 interest. 



On the 28th of August I paid a visit to the north-west coast 

 of Hoy, and found Drosera anglica in abundance, and Vaccinium 

 uliginosum sparingly, and in the marshes above Rysay Schcenus 

 nigricans and Eleocharis multicaulis, both of which I also found 

 in several places in the mainland. 



On the 31st Stachys ambigua was in flower at Kirkwall. Near 

 Piggar, and in several other places round Swanbister, Anthemis 

 nobilis occurs in plenty and apparently wild in one marshy 

 field in particular, where it covers a large extent of ground, and 

 is now at all events perfectly naturalized. 



At Swanbister there is a tract of low land called the " Fidge," 

 which used to be overflowed by the sea at spring tides, but is 

 now protected from this by a sea-wall built by Mr. Fortescue. 

 Here there are a good many of the plants that are to be found 

 in salt marshes, Salicornia herbacea, Cakile maritima, Alsme ma- 

 ritima, Sagina maritima, Carex extensa, Eleocharis uniglumis, 

 Ruppia rostellata, Potamogeton filiformis, Blysmus rufus, and one 

 plant of Stenhammaria maritima. On the rocks called " Bar- 

 nory," to the south of this, Ligusticum scoticum and the maritime 

 form of Pyrethrum inodorum were seen ; both of these plants also 

 occur in profusion in the island of Burray along with Silene 

 maritima. 



Avena fatua and strigosa are found in most of the turnip- 

 fields, &c, and appear to be quite indigenous. Festuca ovina 

 var. vivipara is also common, and Radiola millegrana is to be seen 

 in most of the moors. 



There are a few bushes of Populus tremula and Rosa villosa 

 on the clhTs, on the east side of the Wauk-mill bay between Kirk- 

 wall and Swanbister. 



These are all the plants which I met with that are worth 

 noticing ; but on my next trip to Orkney I hope to be able to 

 visit the north isles, which may perhaps add some others to the 

 list, and make a trip to Orkney of sufficient interest to attract 

 botanists more competent than myself to examine its flora. 



84 Great King Street, Edinburgh, Feb. 5th, 1850. 



XXVII. — Descriptions of Aphides. By Francis Walker, F.L.S. 



[Continued from p. 28.] 



77. Aphis Mali, Fabricius. 

 Aphis Mali, Fabr. Ent. Syst. iv. 216; Syst. Rhyn. 298; 

 Schrank, Faun. Boic. ii. 116; Gbtze, Ent. Beit. ii. 317; Stew. 



