THE CANADIAN ENTOMOLOGIST. 221 



the gaps existing in the knowledge of the history and earlier stages of 

 this beetle. Our most skilled field observers tried their hands in this 

 investigation, scores of beavers were carefully combed from head to tail, 

 tiie contents and surroundings of beaver dens, either of a dry, moist or wet 

 nature, were thoroughly sifted, then packed up, shipped to Washington 

 and here again subjected to the closest scrutiny. All of no avail ; our 

 knowledge of the natural history of Platypsyllus has not advanced, a 

 single step ; even that mysterious object the " ultimate larva" has never 

 been found or seen again, and stands out prominently as a sad example 

 of disconnected solitude. 



American contributions towards a classification of Coleopterous larvae 

 are very few, but we have a large number of scattered descriptions of 

 single species. Some of this descriptive work has been excellently done, 

 but a large proportion of these descriptions, both in scientific and 

 economic literature, leaves much to be desired. There seems to be a 

 notion on the part of some writers that it is a meritorious thing to draw 

 up as quickly as possible and publish a description of any Coleopterous 

 larva. If we examine such descriptions it will be found that they are 

 not of any popular value because the untrained reader cannot understand 

 them anyhow ; nor are they of any scientific value because the student 

 cannot find any tangible points in them. Such writers do not seem to 

 be aware of the fact that there are many Coleopterous larvge provided 

 with six legs, the body being more or less flattened, the head a little 

 darker and the thoracic segments a little longer than the abdominal 

 segments, which are more or less transversely wrinkled. Quite a number 

 of larvae also have a Y-shaped mark on the head. Much better descrip- 

 tions than those just characterized were excusable in bygone times when 

 there was little known of the classification of Coleopterous larvae, or when 

 what little there had been published was generally not accessible to the 

 American entomologist ; but to-day where, in the works of Perris and 

 Schioedte, we have safe guides to the classification of Coleopterous larvae 

 of many families, descriptions of such larvae should no longer be the 

 result of momentary impulse but of a good deal of study and comparison. 



It will take many years of hard work before the biological material 

 accumulated in the collections mentioned above can be adequately 

 worked up, and this work will be the more retarded, in my opinion, 

 because I fully side with those who believe that at the present state of 

 biologic science descriptions of Coleopterous larvas ought to be accom- 



