234 



gland of the male sexual organ of Amblychila (Fig. 9 by is 

 more dilated than in Omus and the bending of the testis is in 

 the reverse direction ; there is also in Omus a double pair 

 of long accessory tubes discharging their contents into the 

 vas deferens, each pair of these tubes uniting near their inser- 

 tion. The tip of the penis is acute in Amblychila (Fig. 13 JL) 

 but is rounded in Omus (Fig. 13 ^). The last abdominal 

 segment is emarginate in all the genera of our fauna except 

 Amblychila. I do not know whether this emargination corres- 

 ponds with the form or position of the tip of the penis, or not, 

 but it is certain that most, if not all, the species of the different 

 genera fl}' around in copula, and the emargination may help to 

 make this possible. 



In looking over the family of Cicindelidae in a speculatory 

 way, I drew the inference that the line of descent diverged 

 (probably in the mesozoic age) into branches, the lowest^ 

 and certainly the oldest of which is still represented in the 

 genus Amblychila. In Omus, Tetracha, Cicindela pilatei, C. 

 maga, C. cursitans and C. celeripes we have an aberrant lesser 

 branch, the latter genera being closely linked with the rest of 

 the Cicindelidae. 



Contemplating the law of adaptation and heredity, I arrived 

 at the conclusion that the prototype of Amblychila formerly 

 lived on the shores of the great intercontinental eulf in cre- 

 taceous times, before the arrival of Cicindela hirticollis and 0. 

 lepida,^ and was in those ages provided with a more specialized 

 structure, which by degrees became retrograded and inherited, 

 when its survivors adapted themselves to the clay-banks of the 

 undulating prairies of Colorado and Kansas. It probably for- 

 merly led a life, like its congeners in Mexico and South 

 America, on leaves of trees, along the shores of the great 

 gulf; the consequent breaking up of the latter into innumer- 



1 The figures referred to are on Plate 1. 



2 Deficient in organ of sight, less specialized in organs of reproduction and in larva, 

 reduced in abdominal segments and wanting wings. 



8 LeCorite: Address of Retiring President (Proc. Amer. Ass. Adv. Sci., 1875 [v. 24], 

 p. 1-18), p. 4. Horn: Notes on some coleopterous remains from the bone cave at 

 Port Kennedy, Penna. (Trans. Amer. Entom. Soc, 1876, v. 5, p. 241-245) (Misc. 

 papers on Amer. coleoptera, p. 241-245), p. 241. 



