376 Geological Society. 



his terrors. To assist in rendering these glorious mutual relations of all 

 parts of creation familiar to the minds of the multitudes whom daily lahours 

 of mind and body too much occupy to allow of due leisure for these contem- 

 plations, is the chosen province of the members of the Linnean Society. 

 They are thus devoted ministers of God ; and while their labours are duly 

 directed to the vindication of his ways to man, to the manifestation of his 

 glory and goodness, they deserve high honour as useful citizens ; they insure 

 to themselves the best of blessings through time, and, in eternity, the appro- 

 bation of their God. 



I believe I said something on the history of natural science ; but this I 

 have printed in a slight outline of science, caWeA Int7'bduction to ihe Cata- 

 logue of the Ashmolean Miiseuvi. Yours, &c. — J. S. Duncan. JNew College , 

 Oxford, June 11.1829. 



June 2. — Read. A communication from 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 descriptions, 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 infe- 

 rior larynx, and the hronchice. 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 con- 

 traction of the membrana typaniformis, and from the power of altering the 

 form of the bronchiae. The muscles 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 conformations of the 

 organs of voice, in various birds, were accurately described and compared. 

 The author states that these are least complex in the Falconidse, some of 

 the Insessores, almost all the Rasores, Grallatores, and Natatores ; more 

 complex in the Psittacidae, who alone possess three pair of true muscles of 

 voice ; but most complex in the Corvi, starUng, larks, thrushes, finches, 

 warblers, swallows, &c., which all have five. The convolutions in the tra- 

 cheaB 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, entitled, Recherches sur la Structure comparc'e 

 et le Develloj)pement des Animaux et des Vegetaux. 



Art. V. Geological Society. 



March 6. — Read. An Account of a remarkable Fossil Plant in the 

 Coal Formation of Yorkshire ; by John Lindley, Esq. F.G.S. F.R.S. &c., 

 and Professor of Botany in the University of London. 



This plant was described as a fern, resembling, in most respects, the 

 Trichomanes renif6rme, a recent species found in New Zealand, but 

 differing in the nature of its vernation. It was said to exhibit distinct and 

 unequivocal traces of the marginal fructification peculiar to the genus 

 Trichomanes. After comparing it with the fossils comprehended by 

 M. Adolphe Brongniart in his genus Cyclopteris, and showing that it was 

 not referable to any known species of that group, the author concluded 

 by assigning to it a specific character, and the name of Trichomanes 

 rotundktum. 



Ap7il 3. — Read. A paper on the Bituminous Schist and Fossil Fish 

 of Seefeld in the Tyrol, by Roderick Impey Murchison, Esq. Sec. G.S. 



