102 GRAMMAR OF ENTOMOLOOy. 



smaller ; in the females of all bees, wasps, and 

 insects of the same form, it is the last segment, 

 the telum not being present in its usual form. 



337- The thirteenth, or last segment (telum), 

 is usually the smallest of them all ; it is often 

 conical, terminating in a point: in the females 

 of bees and wasps it is wanting ; its place is, 

 however, supplied by a sting, into which it is 

 converted. No male insects have a sting. 



338. Each of these thirteen segments have a 

 superior surface, or back (scutum) ; an inferior sur- 

 fece, or breast (sternum) ; and two lateral surfaces 

 or sides (pleura) : the scutum and sternum are 

 generally much more prominent parts than the 

 pleura. 



339. The scutum of each segment is occa- 

 sionally transversely divided by sutural lines 

 or indentations, into four smaller portions, called its 

 first, second, third, and fourth sections (prcescutum, 

 scutum, scutellum, post-scutellum) ; of these, the 

 praescutum is the section nearest the head; 

 the others follow in succession. These sections 

 are readily to be distinguished in the prothorax 

 of a locust, and some other instances ; but fre- 

 quently all trace of division is lost, as in the pro- 

 thorax of a beetle, or the octoon of a wasp. 



340. The sternum is occasionally divided by 

 sutural lines or indentations, into four smaller 

 portions, called its first, second, third, and fourth 

 sections (prcesternum, sternum, sternellum, post- 



