Si ON THE HABITATIONS AND 



between the membranes, composing the upper and 

 under cuticles of the leaves. These nests are of an 

 oblong shape, and so artfully joined with silk threads, 

 that the seam is hardly discernible, even with the 

 assistance of a powerful microscope ; they are of a 

 horn shape, cylindrical in the middle, with the an- 

 terior orifice circular, and the posterior opening of a 

 triangular form. If these habitations were cylindrical 

 throughout, the contraction of them would be an 

 operation requiring comparatively very little me- 

 chanical skill ; but, as the two ends are quite dif- 

 ferent, so there is a necessity for both sides being 

 dissimilar in their curvatures ; and we have the 

 assurance of Reaumur, that they require the same 

 nicety of imitation and junction as the different 

 pieces of vi'hich the back of a coat is composed. 



Speaking of insects of this tribe, Mr Spcnce says, 

 " Their proceedings I had the pleasure of witnessing 

 a short time since upon the alders in the Hull 

 Botanic Garden. More ingenious than their brethren, 

 and willing to save the labour of sewing up two sides 

 in their dwellings, tlicy insinuate themselves near the 

 edge of a leaf instead of in its middle. Here they 

 form their excavation, mining into the very crena- 

 tures, between the two surfaces of the leaf, which, 

 being joined together at the edge, there form one 

 seam of the case ; and, from their dentated figure, 

 give it a very singular appearance, not unlike that 

 of some fishes, which have fins on their backs. 



