OF THE ANNULOSA. 415 



was, that it appeared to me of all the theories yet invented 

 the most hkely to serve in the end to effect the reduction 

 of the Annulosa to a general plan of construction, ana- 

 logous to that on which the Vertehrata are now known 

 to be framed. 



But I had also another reason, connected in no small 

 degree with the chain of affinities, which I have attri- 

 buted to the class of Mandibulata. It is, that, if the theory 

 of M. Latreille be true, there can remain no farther doubt 

 as to the accuracy of Mr. Kirby's opinion on the natural 

 situation of the Strepsiptera being close to the Coleo^ 

 ptera ; for then those appendages to the thorax which he 

 terms elytra, may really be such, or at all events be the 

 substitutes of wings. MM. Lamarck and Latreille have 

 indeed both declared themselves against this doctrine, and 

 have consequently accounted the genera Stylops and 

 Xenos to be Dipterous ; a conclusion peculiarly harassing 

 to the entomologist, who may wish to adopt it, from no 

 insects whatever being more unlike than these to the com- 

 mon type of the order of Diptera. Assuming, however, 

 the truth of M. Latreille's theory as to the tendency in the 

 thoracic segments to have each a pair of appendages, the. 

 elytra of a Coleopterous insect are wings, serving in- 

 deed as a case for the shelter ,of the other pair, but not 

 the less answering to the place of true wings in other 

 Hexapod orders, or of two feet in Crustacea. But this is 

 not only the exact case with the elytra or thoracic appen- 

 dages of a Xenos, but the insect would be theoretically 

 imperfect without such organs, since it has neither haU 

 teres nor squamulez to take the place of a pair of wings as in 

 the Diptera. Here then, to mention nothing of the more solid 

 arguments to be drawn from the construction of the raautl)> 



