HANCOCK 25 



removed. A part of the phylogenetic history of the species 

 is recapitulated in the larva and pupa, and there is suggestive 

 evidence that the early progenitors of living forms presented 

 a highly cristate condition of the pronotum, as shown now in 

 some forms further south. It will be seen that in all the 

 genera of the temperate region of North America the median 

 carina of the pronotum in the larval and pupal stages presents 

 a cristate character, and there is but one sj:rongly marked 

 sinus situate inferiorly. The cristate character in the larva is 

 correlated with the acquiring of a numerical increase of the 

 antennal articles. These larval characters are retained in 

 adults of such specialized forms as Clwripliylliim. It is prob- 

 able the ancestors of the Tettigidse had but one sinus inferiorly 

 located on the pronotum, while the wings and elytra were 

 still undeveloped and metamorphosis was less complete. The 

 knowledge gleaned from the post-embryonal studies show that 

 the Tettigidffi are a remarkably highly specialized group, doubt- 

 less originally starting from the lowest portion of the trunk 

 from which arose the various other groups of the Acrididse, 

 and that they (Tettigidae) occupy a distinct position.* 



ENEMIES. 



During the life of these little Tettigians they are more or 

 less constantly in danger of enemies among the arachnida, 

 insecta, and some of the vertebrata. The larva of a red mite 

 (Trombidian) is one of the most frequent sources of annoyance. 

 Acting as a parasite the Trombidian larva clings on the body 

 and attaches itself out of the reach of the victim. There it 

 remains to sap the juices of the host's body. It is found on 

 many species. Among insect pests, ants and bugs are some- 

 times deadly to them. In a wet ditch in June the writer found 

 a number of small dark-brown ants dragging along the ground 

 a female Tcttix ornatus which had just been killed by them. 

 When endeavoring to capture some Tettix at the same place 

 my attention was drawn to a colony of these ants acting in a 

 panicky state of excitement, the cause of this being that they 

 had darted upon the insect the author was pursuing, tumbling 



* The embryology is left out here for future consideration as a separate contribution. 



