1S13.] 



L'lnncean Society, 



225. 



dered as a new species. He calls it chama Gualtieri. Six species 

 of halyotis, Mr. Brooks was not acquainted with the place 

 where any of these were found, except one, and that was the 

 Pacific Ocean. It is very much to be lamented that the habita- 

 tion of shells, and the animals that inhabit them, are not more 

 attended to by collectors. It is the only way to perfect this diffi- 

 cult department of natural history. 



At the meeting which took place on the 16th February, the 

 following communications were read :— 



A letter from Mrs. Taylor, with specimens of a gelatinous 

 plant, conceived to be a new species of lichen, which grew two 

 successive years near her house in Devonshire. 



A letter from Mr. Hoy, at Gordon Castle, Scotland, giving an 

 account of a fish cast ashore near Gordon Castle, the trichiurus 

 lepturus, not hitherto conceived to exist upon the British coast. 

 The specimen, without the head, was about 1 2-1 feet long. 



A letter from Dr. Smith, President of the Linnsean Society, 

 giving an account of the astragalus campestris, a new British 

 plant, lately discovered on a rock in Angus-shire, by Mr. George 

 Don. It is a splendid plant, and quite alpine. It was described 

 by Haller, In the Flora Danica it is figured under the name of 

 astragalus uralensis. Wildenow describes it under the name of 

 astragalus sordidus. 



An account by Mr. Kirby of a new species of insect, from an 

 imperfect specimen sent him by Mr. Sowerby. 



An account of a tree observed in the West Indies by Mr, 

 Pursh belonging to Jussieu's order of EuphorMas and to the 

 Monoecia Monodelphia of Linna?us. It constitutes a new genus, 

 Mr. Pursh names it, in honour of Dr. Hosack, of New York^ 

 Hosackia laurina. 



IMPERIAL INSTITUTE. 



Account of the Labours of the French Imperial Institute for IS 12. 



{Continued from p. 156.) 



Researches of M, Biot on Light, 



In the notice published last year of the labours of the Class^ 

 we have given an account of the researches read to the Institute 

 by M. Arrago on the colours exhibited by plates of mica^, sul- 

 phate of lime, and rock crystal, when they are exposed to a 

 polarized ray. Since that time M. Biot has presented to the 

 Institute a suite of memoirs, in which he announces that he 

 has discovered by experiment the exact laws of these phenomena, 

 that he has expressed them by mathematical formulas, and that 

 he has reduced them all to one general fact, from which all the 

 phenomena may be deduced by calculationc We shall give m 



Vol, L W IIL P 



