212 
is an interesting subject, be should endeavour to bring it 
before the next meeting. 
The discussion “On the cause of metallic lustre upon the 
wings of the Lepidoptera” was resumed. Mr. Latham 
stated that he saw no reason to alter the views he had ex- 
pressed ; hut since the last meeting Mr. Watson had called 
his attention to an article in the “Annales des Sciences 
Naturelles” for February, 1835, by Bernard Dechamps, “Sui- 
les Ailes des Lepidopteres,” which contains much information 
upon the scales and the cause of their brilliance ; he (Mr. 
Latham) had translated and printed extracts from the paper ; 
copies were handed round to the members present, and may 
be had (gratis) at the Society’s rooms, or from the Secretary 
of the Microscopical Section. 
A Paper was read by Dr. Thomas Alcocic “ On the 
Tongues of Mollusca.” 
The Author remarked upon the great variety and beauty 
of these objects, and pointed out their scientific value as a 
help in the classification of shells. On investigation the 
tongues were shown to arrange themselves into four groups, 
according to the pattern or type of the lingual dentition, and 
these groups were stated to correspond with four of the orders 
established by Cuvier, on the characters of the breathing 
organs. The four orders illustrated were the Pectinibran- 
chiata, the Scutibranchiata, the Cyclobranchiata, and the 
Pulmonata ; and he believed that, on the evidence of the 
teeth, it will be necessary to re-establish the order Cyclo- 
branchiata as distinct, instead of including it in the 
Scutibranchiata, as is done by our latest authorities. 
The Author had examined many specimens of Buccinum 
undatum of both sexes, a series of which were exhibited to 
prove that the number of points on the central teeth in this 
