10 THE CANADIAN ENTOMOLOGIST. 



duce no swelling or gall, as do the larvre of /. Hordei, but feed upon the 

 soft tissue of the interior of the stalks. They are about .15 of an inch 

 long, rather slender, tapering slightly toward either end, footless, but when 

 in motion seeming to have the power of pushing out the substigmatal 

 portion of the segments, a distinct transverse head about two thirds the 

 width of body, with a pair of brown jaws. Color yellow, approaching a 

 pale orange. 



Pupae. — These vary from about .08 to .12 of an inch long, are black 

 and of the usual hymenoi^terous form. About four fifths of the larvae 

 observed changed to pupae and produced the imago, or died, the past 

 season from July 20th, when the first imago was found, to August 20th, or 

 perhaps better, underwent their changes between July 8th and August 20th; 

 but I think this the effect of the dry season. Those examined the last of 

 November were in the pupa state in the interior of the stalks down close to 

 or in the substance of the joint, both in the fields and in my breeding 

 jars. Those were in the larva state the last of August. It is probable they 

 pass the winter in the pupa state under ordinary circumstances to produce 

 the imagines in the spring, and tliat those hatching during July and August 

 perish without ovipositing. 



Described from i o females and 4 males. 



I take pleasure in dedicating this species to Robt. Allyn, LL.D., 

 President of the Southern Illinois Normal University, as a slight acknow- 

 ledgment of valuable aid and encouragement he has rendered me in my 

 work. 



IsosoMA Elymi, n. s. 



Length .07 of an inch. A little more slender than the preceding; 

 width of head and middle of thorax .02 of an inch. Color black without 

 metallic lustre. Head and thorax very sparsely covered with hairs ; 

 antennse scarcely enlarged at the ends ; wings hyaline, microscopically 

 hairy ; legs rather more slender than in the preceding species, or in /. 

 Hordei, all fuscous throughout, except that the joints are a little pale. 

 Abdomen about as in the other species, the ovipositor slightly exserted. 



Larvae. — These are found on the interior of the culms of Elymus 

 Canadensis in about the middle inlernodes of the stalks, very much as the 

 larvae of the preceding species are to be tound on the interior of wheat 

 culms. While, however, the wheat larvae are generally just above the 

 joint, these may be found in any part of the interior of an internode. 



