Zoological Club of the Linnean Society. 131 
brana tympaniformis, and from the power of altering the length of the 
bronchie. 
The muscles of the inferior larynx vary in number from one pair to 
five. They are least complex in the Falconide, some of the Insessores, 
and nearly the whole of the Rasores, Grallatores, and Natatores. In 
the Psittacide they are more complex, consisting of three pairs, a num- 
ber which is not met with in any other family of birds. They attain the 
extreme number of five in the Corvi, starlings, larks, thrushes, finches, 
warblers, swallows, &c. 
Z)JOLOGICAL CLUB OF THE LINNEAN SOCIETY, 
May 12, 1829.—A paper On the Organs of Voice in Birds: by W. 
Yarrell, Esq., F.L.S., was read by the authour, who subsequently illus- 
trated the subject by references to numerous drawings which he exhibited 
to the meeting. A discussion ensued in which the Chairman, Mr. 
Brookes, and Mr. Yarrell took part. 
May 26.—Mr. Yarrell exhibited, for the Rev. L. Jenyns, F.L.S., a 
specimen of Plecotus barbastellus, recently taken in Cambridgeshire, and 
stated that this was the second instance recorded of its occurrence in 
England. 
June 9.—The Rev. W. Kirby exhibited drawings of numerous Insects 
intended for publication in the forthcoming Fauna of North America. 
Among them were types of several new genera of Coleoptera, and also a 
new species of Procerus, a genus hitherto confined to the old Continent. 
A paper On Luminous Insects : by R. Chambers, Esq., F.L.S., was 
read by the authour. 
June 23.—Mr. Yarrell exhibited numerous drawings and preparations 
of the trachee of Birds, for the purpose of illustrating his paper “ On 
the Organs of Voice,” which was read at the meeting of May 12. He 
explained them to the members present at some length, pointing out the 
most simple form, and proceeding to the more complex. 
November 24.—Mr. Leadbeater exhibited specimens of several spe- 
cies of Psittacide, which he believed to be new to science. Among 
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