2 Trans. Acad. Sci. of St. Louis. 



— 10° F. Even here in St. Louis the mantis population 

 survives year after year, apparently unaffected by the 

 occasional extremes of 15° to 20° below zero. Its fre- 

 quent occurrence in this region was known to Riley in 

 1868, and during the years 1908-1911, old egg-cases were 

 taken at Meramec Highlands, Mo., Creve Coeur Lake, 

 Mo., and Forest Park, St. Louis, Mo., while the greatest 

 source of egg-case supply was the board fences in gar- 

 dens in the southwestern part of this city. NjTiiphs were 

 also found at Falling Springs, 111. 



Anatomy. 



The internal or external anatomy of the insect has 

 never been worked out to any considerable extent, but 

 the following general notes may help to make clear the 

 discussions which follow. 



The head is attached to the prothorax by a flexible 

 membrane, which makes it possible for the head to turn 

 ahnost completely around (Plate I) and the animal 

 when quietly at rest, awaiting its prey, stealthily moves 

 its head in all directions, sometimes holding it in one 

 difficult position for many minutes. The mouth parts 

 are of course formed for biting. Besides the two com- 

 pound eyes, the head contains three simple eyes. Just 

 how these function or what is their distance of vision is 

 not known, but that they are highly developed for the 

 purpose of distinguishing good prey, on the wing or 

 moving about, is obvious. The insect will eye its victim 

 serenely, sometimes for many minutes, before making the 

 final leap, or back away from distasteful food when of- 

 fered it. 



The prothorax is greatly modified and bears the highly 

 developed pair of forelegs. These appendages are ex- 

 tremely useful to the animal for catching and holding its 

 prey; without these in their highly developed spinal con- 

 dition, the animal would have no means of offence or 

 defence. Their power is really surprising ; the sensation 

 in placing one's finger between them is anything but 



