THE SYNTHETICAL METHOD. 463 



likeness to a Folyxenns, while that of the genus Gyrinus 

 resembles a Scutigera. Thus does every step we take in 

 the study of nature, unfold to the view new instances of 

 her attachment to certain general principles of form, amid 

 a variety in the details which truly appears to be inex- 

 haustible. 



The following indications, which relate rather to the 

 contents of the tribes than to the order of affinity in which 

 these contents are distributed, will be found useful, not as 

 being the truth itself, but as being guides to the truth. It 

 must be well understood, however, that the designation of 

 some of the contents of a tribe is not synonymous with the 

 designation of the distinctions and affinities affecting the 

 groups which compose it. The latter I do not aim at ; and 

 even in the specification of the probable contents of a tribe, 

 there are many chasms yet to be filled up, particularly in the 

 circles of Apod, Anopluriform, and Thysanuriform larva?. 



The types of the tribe of Chilopodiform larva? are cer- 

 tainly those carnivorous insects which have four maxillary 

 palpi. These form two great groups, one of which con- 

 sists of the genera Carabus and Cicindela of Linnaeus, and 

 the other of the Hydrocanthari of Latreille. To the same 

 tribe the genus Hydrophilus of Geoffroy ought to be 

 ascribed ; from which, by means of Sphteridiurn, we enter 

 among the Chilognathiform larva?. The type of this tribe 

 appears to be the genus Scarabaus of Linnasus, or those 

 insects to which, after the example of Dumeril, I have 

 given the name of Petalocera. The tendency of Chilogna- 

 thiform larva? is herbivorous ; and among them we have the 

 Linna?an genera Lucanus, Ptinus, Byrrhus, Hister, Elater, 

 Buprestis, and part of Tenebrio and Dermestes. By means 

 probably of the genus Bostrkhus of Geoffroy, we quit the 



