28 GEO. H. HORN, M. D. 



Descriptions of tlie larvae of the North American genera 

 of CICINDEL,ID.E, also of DIC^L,IJS with a note on 

 RHYSfCHOPIIORUS. 



BY GEORGE H. HORN^ M. D. 



Through the exertions of Mr. E. W. Guild of Manhattan, Kansas, 

 the larva of Amhh/chila has at last been made known to the scientific 

 world. Hearing that I was about to publish a description, Dr. Hagen 

 of the Museum of Comparative Zoology at Cambridge, placed at my 

 disposal the larvae of the other genera of Cicindelidae. 



The accompanying plate (II) will enable the forms of these larvse 

 as well as their different members to be compared so that the resem- 

 blances and differences will be at once apparent. 1 have thought 

 it advisable to give lateral instead of the dorsal views usually given 

 because the larvae are naturally in the position in which I have 

 represented them, and it always seemed to me very unnatural to 

 represent a Cicindela larva as if walking when in fact it is almost 

 impossible for them to do so at all. The larvaa of Cicindelid^ live 

 in holes in the ground excavated nearly vertically and when on the 

 watch for prey the thorax and head are on the level of the top of the 

 hole, the mandibles widely separated. In this position they remain 

 until a small insect is captured when they retire and leisurely devour 

 it, the debris is always pushed out and thrown some distance by a 

 quick motion of the head and thorax. The larva is enabled to main- 

 tain this position at the mouth of the burrow by means of the hooks 

 on the back of tlie fifth abdominal segment and by the anal segment 

 itself. The natural position of each larva in its burrow is that repre- 

 sented on the plate, and it is absolutely impossible for these larvas to 

 assume the form in which they are usually represented. 



In all the larvae of Cicindelidae the spiracles have a precisely simi- 

 lar arrangement. Dicseliis has the anterior spiracle in the mesothorax. 

 Attention should be directed to the more accurate description of the 

 position of these organs as they are usually either entirely passed by 

 or spoken of as "spiracles normal." 



The larvae of Carabidae as far as known are active and cursorial, 

 seeking their prey, while the larvae of -Cicindelidae are solitary, 

 sedentary and lie in wait for prey, never changing their place. 



