1885.] 



THE ENTOMOLOGIST. 



;8i 



and Eiley liave relegated these to the rank of mere varieties. 

 According to Itiley, Professor Cook's new species agrees witli the 

 tritici variety (Fig. 8), which, tliough usually causing the straw to 

 swell, may effect its solidifying and hardening in the way represented 

 in 1m fj. 1. 



Fig. 0, 

 Js'jsmna gramU, larger Joint-worm Fly, female— After Riley. 



Fig. 10. 



Is-jsomw. grande.—d, larva ; e, antenna ; /, mandible ; g, pupa.— After Riley. 



Insects represented by the last two figures are known only as 

 females, and sum up the three species known to infest wheat. The 

 larva of Isosoma Jiordci abounds usually near the joint, producing 

 veritable galls, the affected stalk solidifying and the external swell- 



