426 GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 



Mr. Scudder's arrangement appears to depend upon tlie position of the 

 wings during the different stages of growth. As these organs in the 

 Saltatoria change position during the different stages of growth, he con- 

 siders this group as ranking higher than the others, in which they retain 

 their primitive position. But does this correspond with the other im- 

 portant characters ? With some it undoubtedly does, but with others 

 it does not. Lacaze-Duthiers, who has studied with much care the 

 genital organs of the various orders, states,* that if we take the devel- 

 opment of the ovipositor as a guide, the divisions of this order will 

 arrange themselves as follows : Locustidw, Grytlidce, Mantidw, Fliasmidw, 

 Blattidce, Acrididw, Forficulidm ; thus placing all the families of the 

 non-saltatorial, genuine Orthoptera between the two sections of the Sal- 

 tatoria. 



Gerstaecker t brings the families of the saltatorial group together, but 

 in a different order from that of Mr. Scudder, placing Gryllodea as the 

 highest of this group, and next to Fhasmidea. 



If we examine carefully the elaborate researches of Leon Dufour, upon 

 the Anatomy and Physiology of the Ortlioptera, published in the 31e- 

 m'oires de VInstitut of France, vol. vii, 1841, we will see the difficulty of 

 attempting to form an arrangement of the families based whollj' ou 

 internal anatomy. The nervous system, digestive apparatus, genital 

 organs, &c., will lead to different results. For examiDle, if we take' the 

 nervous system as our guide, the result will be to lilace the Acrididw at 

 the head of the column, and, according to L. Dufour, the Ortlioptera at 

 the head of the class.| On the other hand, if we examine the digestive 

 apparatus, we find the salivary glands of the same family the least de- 

 veloped of any in the order. And these contradictious are so well 

 balanced that the i^reponderance is not sufficiently marked to form the 

 basis of a system. There is perhaps one excei^tion to tbis statement, to 

 wit: if guided by internal anatomy alone we will, jjerhaps, be compelled 

 to i)lace the Forficiilidw as the lowest in the order ; and it is quite i)os- 

 sible that such is its proper position. 



If we take the external form as our guide we cannot but be struck by 

 the strong resemblance of the GeutlwpMli and Udeopsyllwtothe crustacean 

 form. And when we learn the habits of the former this resemblence 

 assumes still more importance, as we find them along the margins of 

 water-courses, and in the vicinity of damp places, hiding under stones 

 in caves, and away from the rays of the sun. 



I have often had my attention called to the general resemblance of the 

 Tridactyli to the Tettigi, and the anatomical researches of Leon Dufour 

 show this external similarity to be more than fancied, for he remarks: § 

 •' That the genus Tetrix, (Tettix,) founded by Latreille, appears to have 

 been created by nature to serve as the connecting-link between the 

 Tridactyli and Acridii." If we trace the habits of these two groups, the 

 suggestion of this author seems to be borne out by the result. The Tri- 

 dactyli are found along the banks of streams and ponds ; in fact, I have 

 noticed myriads of them leaping on and off' the surface of the water 

 when the soft sand into which they had burrowed was disturbed. 



At the next step from the moisture toward the dry localities we find 

 the Tettigi. Find a spot where the summer sun has dried up a small 

 pond of water and there you are aj)t to notice an abundance of speci- 

 mens of both these groups ; at least, this has been the case in that part 



* Aunales des Sci. Nat. ZooL, torn, xvii, (1852,) p. 237. 

 t Carus, Handbucli der Zoologie, II. 

 t Mem. de I'Inst., vii, 282. 

 $ Op. cit., 315. 



