136 Geological Sociefy. 



May 25. — The Anniversary was held at the Society's House, 

 A. B. Lambert, V.P. in the chair ; when the following were appointed 

 officers. 



Presidejit: Edward Lord Stanley, M.P. — Vice-Presidents : A.B. 

 Lambert, Esq. F.R.S. ; W. G. Maton, M.D. F.R.S. ; E. Forster, 

 Esq. F.R.S. ; and R. Brown, Esq. F.R.S. &c. — Treasurer: Edward 

 Forster, Esq. F.R.S. — Secretary: J.E.Bicheno, Esq. F.R.S. Assis- 

 tant Secretary : Richard Taylor, Esq. F.S.A. &c. — Also to fill the 

 vacancies in the Council : Thomas, Marquis of Bath, F.S.A. ; W. 

 J. Broderip, Esq. F.R.S.; R. E. Grant, M.D. F.R.S. Ed.; John 

 Lindley, Esq. F.R.S. &c. ; and Nathaniel Wallich, M.D. F.R.S. &c. 

 The annual dinner was enlivened by the presence of several much 

 esteemed naturalists from various parts of the kingdom. 



June 2. — Read a communication by Wm.Yarrell, Esq. F.L.S.&c. 

 " On the Organs of Voice in Birds." The author here pursues the 

 subject of his former paper on the Tracheae of birds, and gives de- 

 scriptions accompanied by figures of the numerous muscles by 

 whose action the varied powers of the vocal organs of birds are 

 governed. Their organs of voice consist of four parts: the glottis 

 or superior larynx, the tube of the trachea, the inferior larynx, and 

 the bronchicB. Great difference exists in the relative length of tube, 

 short ones producing shrill notes, as in singing birds, and vice versa 

 in waders and swimmers. Strong broad cartilaginous rings give 

 loud and monotonous voices, and slender rings with large space 

 between admit variety of tone. Some of these varieties result from 

 the dilatation and contraction of the membrana tympaniformis, and 

 from the power of altering the form of the bronchiae. The mus- 

 cles of the inferior larynx vary from one pair to five. 



June 16. — In the remainder of Mr. Yarrell's paper, the reading 

 of which was concluded at this meeting, a great many curious con- 

 formations of the organs of voice in various birds were accurately 

 described and compared. The author states that these are least 

 complex in the Falconidae, some of the Insessores, almost all the 

 Rasores, Grallatores, and Natatores ; — more complex in the Psitta- 

 cidffi, who alone possess three pair of true muscles of voice ; but most 

 complex in the Corvi, starling, larks, thrushes, finches, warblers, 

 swallows, &c., which all have five. The convolutions in the trachea 

 of some species are aptly compared to the additional crooks fixed 

 to the French-horn in order to play in a lower key. — A part of a 

 memoir by M.Dumortier was also read, intitled ^' Kec/ierches surla 

 Structure comparee et leDevelloppement desAnimaux et des Vegetaux." 



(iEOLOGICAL SOCIETY. 



June 19.— A. B.De Capel Brooke, Esq., of Lower Brooke Street j 

 James Morrison, Esq., of Portland Place ; and Daniel Sharpe, Esq., 

 of New Ormond Street, — were elected Fellows of this Society. 



A paper " On the occurrence of agates in the dolomitic strata of 

 the new-red-sandstone formation in the Mendip Hills," by the Rev. 

 W. Buckland, D.D., V.P.G.S., F.R S., &c., &c., was read. These 

 agates are ploughed out of the surface of the fields at Sandford, near 

 Banwell, and are nearly allied to the potntoe-stones, which abound in 



the 



