Ixix 



3. Heterooastra. Abdomen alike in both sexes ; elytra with a distinct 

 lateral fold on the inner surface. Fam. Calandrida, Anthribida, Scolytida 

 and ApionidcB.-i- 



These insects are regarded by Dr. Leconte as " the lowest type 

 of Coleoptera, and therefore geologically the oldest. Regarding, 

 then, the fixity of insect types as shown by the resemblance of 

 ancient forms to those of the present time, the uniformity in food 

 and manner of life, and the immense nmnber of genera in this 

 complex, we have a right to expect that there will be a propor- 

 tionally larger survival of unchanged descendants of those species 

 or genera which were first introduced. We will therefore have 

 a more perfect series of connecting forms than can be found in 

 other orders of insects, whose methods of life expose them to the 

 influences of destruction or modification by external circum- 

 stances." A reraarkale Appendix is given, drawn up with much 

 labour by Mr. B. P. Mann, of Cambridge, Mass., of the biblio- 

 graphy of memoirs relating to the Economic Entomology of the 

 Rhynchophora of the United States, relating to the benefits, habits, 

 proposed remedies against, descriptions, injuries, seasons, food, 

 localities and transformations, derived from the ' American Ento- 

 mologist,' the ' Practical Entomologist,' ' New England Farmer,' 

 ' Packard's Guide,' Harris's ' Insects injurious to Vegetation,' 

 Fitch's ' Reports on Insects of New York,' ' Transactions of New 

 York State Agricultural Society,* Riley's ' Reports,' Walsh's ' Re- 

 port on Insects of Illinois,' and ' Canadian Entomologist,' and in 

 ' Psyche,' published in monthly numbers by the Cambridge Ento- 

 mological Club, Cambridge, Mass. 



A remarkable tabular synopsis of the Rhynchophora and their 

 geographical distribution in the difi'erent zoological provinces of 

 temperate North America, has also been published by Drs. J. L. 

 Leconte and G. H. Horn, in the ' Proceedings' of the Amer. Phil. 

 Soc, vol. xvi.. No. 96, in which are tabulated the numbers of 

 already described and new species ; also of the geographical 

 distribution of the genera, whether Atlantic, Central or Pacific, 

 and a similar table of the geographical distribution of the species. 

 The total number of the genera is 270, and that of the species is 

 922. The instances in which similar extraordinary forms occur 



* This classification is opposed by M. Uoelofs, ' Compte-Rendre Soc. Eut. Belg.,' 

 ae December, 1877. 



