158 DR. V. E. SHELFOED ON THE LIFE-HISTORIES AND 



known than those of any other member o£ the group. Geoffroy gave a 

 general account in 1762, to which details were added by Desmarest in 1804 

 and Westwood in 1838. Blisson described the pupa and the last part of the 

 life-history in 1848, and Enock completed the account in 1903. The latter 

 contributed a description of the eggs, the open burrows in which they are 

 laid, and a detailed account of the burrowing habits of the larvse. Several 

 other larvse, pupae, etc., chiefly European, have been described. Ponselle gave 

 an account of the egg and egg-laying habits of C. flexuosa, Fabr., but stated 

 that he was unable to secure any larvse from eggs removed from the soil,, 

 because of fungus attacks. 



Larva\ 



The notable characters of the larvae are the head and prothorax, which 

 close the burrow when the animal is waiting for prey, and the hooks and 

 spines of ihe fifth abdominal segment which enable it to move up and down 

 in the burrow and prevent large prey from dragging it out. Descriptions of 

 the structures of these larv£e are easily accessible in text-books of entomology, 

 &c. Enock's account of their habits and movements is detailed, accurate, and 

 in a general way applies to the whole group. 



Burrows — Soil Inhabiting Forms. 



The burrows are not so well known as the larvae. They differ more in 

 different species than the larvae themselves. They are usually cylindrical and 

 have a circular opening at the surface. The edge of the opening is slightly 

 rounded and perfectly smooth. Surrounding it is a circular area which 

 extends outward, from the edge of the opening for a distance a little less than 

 the equivalent of the diameter of the buri'ow itself. This area the animal 

 keeps smooth and clean by removing all loose earth and packing the particles 

 of soil with its mandibles. This smooth area and rounded edge almost always 

 serve to distinguish the burrows of Cicindelidce from those of other animals. 

 Tiger-beetle burrows occur in horizontal or vertical surfaces, or surfaces 

 sloping at any angle between these two extremes. The general direction of 

 the burrows is vertical or at right angles to the surface, all apparently 

 depending upon the habit of the particular species. Those of some species 

 are curved, as for example C. liyhrida Linn. (Lesne), or straight like those 

 of C. campestris. The depth varies from a little more than the equivalent of 

 the length of the animaPs body, in the case of larvae found in hard soil, to 

 1*25 metres in the case of larvae mentioned by Griddle as occurring at 

 Aweme, Manitoba ; it is related to the character of the soil, temperature, the 

 distance to ground-water, and possibly other factors. 



