232 



HYMENOPTERA. 



UROCERIDyE. 



In the horn tail (Fig. 183) the body is long, and 

 the thoracic rings (Fig. 183, b\ b" , b'") are more 

 loosely connected than in bees. The waist is large, 

 the abdomen not being fastened to the thorax by a 

 peduncle. The tendency of the first abdominal ring 

 to become united with the thorax which we have ob- 

 served in the Orthoptera (locusts, grasshoppers, etc.), 



Fig. 183. 



and which also exists among certain forms of the Co- 

 leoptera and Hemiptera (Heteroptera), as pointed out 

 by Hammond, is found in both the Tenthredinidse 

 and Uroceridae, but the junction is actually known to 

 take place only in the Hymenoptera Aculeata, and 

 there it is correlative with the stinging habits of the 

 insects and the pedunculated abdomen. The oviposi- 

 tor {os) of the horntail is not a saw, but a borer, and 

 is attached near the middle of the lower side of the 



