GEOLOGICAL SUEVEY OF THE TERRITOEIES. 427 



of the country wliere most of my examinations have been made. In the 

 Eocky Mountain region, where there is but little moisture, and tlie land 

 is elevated and dry, individuals of these genera are seldom to be met 

 with. But I will not attempt to develop fully this thought at this time, 

 as I have alluded to it more incidentally than otherwise. 



The attempt to raise the smaller divisions to families, and to give 

 them names with a termination indicating that they are family groups, 

 has been carried to an extent that I think is wholly unwarranted by the 

 distinctions. Family characters, until these groups were broken up of 

 late years by the unnecessary inroads made upon them, were the best 

 marked and most natural of any in the entire class. But how are they 

 now ? I cannot answer in regard to other orders, as my entomological 

 studies have been confined almost exclusively to the saltatorial Orthoj)- 

 tera ; but in this division of this order they are almost wholly worthless. 

 For example, this group, which was formerly generally divided into but 

 three, and never, I believe, into more than five families, is now sejjarated 

 by Walker* into twenty-one ; and Gryllidce, although as comijrehensive 

 as formerly, holds no higher position as a group than StenopelmatidoB, 

 Oedijpodidw, or even the single genus Trigonopteryx. By such an ar- 

 rangement we are told, in effect, that there is less difference between 

 Gryllotalpa and Oecantlms, or Tridactylus and Phalangapsis, than there is 

 between Thamnotrizon and Anahrus, or Opomola and Xiyliocera. Such 

 a system is but adding confusion where there should be order, and 

 renders that mor,e difficult and complex which the increase in scientific 

 knowledge ought to simplify and make plainer and more easily under- 

 stood. 



The family, as has beeuTemarked by Burmeister,t ''is peculiar to the 

 natural system, and by this only is it called forth; Linnaeus and Fabri- 

 cius, who formed artificial classifications, had no families. The charac- 

 ters which distinguish the families are derived not only from their 

 resemblances in structure in general, but also frequently from their 

 economy." Agassizf says, '' Families, as they exist in nature, are based 

 upon peculiarities of form as dependent upon structure." And he adds 

 that they are determined by external outline, which renders the recog- 

 nition of them easy, and in many instances almost instinctive. 



If the rules laid down by these eminent naturalists are to be followed, 

 where are we to find tbat striking difference in form between Acridium 

 alutaceum and (Edipoda Carolina that will place them in different fami- 

 lies, or even between Acridium and Oedipoda, that should cause them 

 to be taken as the types of two different familes ? What striking differ- 

 ence in external foi-m is there between Phylloptera and Flatyphyllum, 

 as to separate them so widely that an entire family can be interposed 

 between the groups to which they belong ? 



When the discovery of new species renders the family unwieldy, it 

 can be divided or subdivided without destroying it, where it is well 

 marked by true family characters. Therefore, while I shall to a greater 

 or less extent retain the subdivisions that have been made, I shall assign 

 to them such value as I think they really have, and shall not attempt 

 to cut down or lessen the families. On the contrary, if I were to make 

 any change, I would rather be disposed to unite the GryUidw and Locus- 

 tidce into one family. 



I find there is considerable difference in regard to the use of the ap- 

 pellation " Tribe," sometimes being applied to groups superior to the 



* Catalogue of the JDemiajytera Saltatoria, Pt. V. 



t Manual of Entomology, translated by Shuckard, p. 595. 



t Methods of Study in Natural History, p. 111. 



