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ON THE CATERPILLARS OF THE SAW- 

 FLIES (TENTHREDINID.E). 

 By J. O. Westwood, F.L.S., &c. 



Probably, it would be impossible to find, throughout the 

 entire range of Zoological science, a more perfect instance 

 in which animals, belonging to one group or order, 

 exhibit an extreme resemblance to those of another totally 

 different group (so as even to deceive, not only ordinary 

 observers, but even practised students), than is to be found 

 in that afforded by the caterpillars or larvae of the family 

 Tenthredinidce or Saw-flies, compared with those of Lepi- 

 dopterous insects. 



On the present occasion, I do not propose to enter into 

 any learned discussion on the principles of analogy and 

 afhnity, typicality, &c, so forcibly suggested by the family 

 Tenthredinidce, but shall simply appeal to the experience of 

 the youngest tyro in Entomology, who has doubtless already 

 been misled by the striking resemblance between the larvae 

 of the saw-flies and those of butterflies and moths. 



The present paper will, therefore, consist of the following 

 divisions : — 



1. The chief points of resemblance and difference between 

 the transformations of the saw-flies and those of Lepidop- 

 terous insects. 



2. A more detailed account of a few of the transformations 

 of the species of saw-flies, selecting those which are the most 

 interesting, from their greater or. less resemblance to the 

 Lepidoptera, 



