218 EDWARD NORTON. 



dots. Fully mature July 31st. An anala2;ous i^all is formed in Europe 

 on various willows by N^ematus fjaUicola, Westw. 



Larva. May 24th it is only about 0.10 long. June 11 it is white, 

 0.10— .13 long. July 24 0.15 long. July 30 0.15— .20 long, pale 

 greenish-white; head pale brown. Legs freely moveable. There was 

 no earth in the jar in which the galls were placed, and most of the co- 

 coons were spun in the galls and a few between them." 



Sept. 9th Mr. Walsh noticed three larvae creeping about in the jar, 

 0.35 — .40 in length, pale cinereous, with pale dusky markings, which 

 lie thought belonged to the Inquilinous genus N. mrndicus^ one of 

 which was bred in the spring from the same lot of galls. 



Rock Island, 111. 



42. N. hospes. 



Ncmatus hospes, Walsh, Troc. Ent. Soc. Phil, vi, ISfiC, 261, ^ %. 



"Absolutely indistinguishable from the normal type of the gall-mak- 

 ing N. s. pomum % 9 ) except that in % the lateral plates of the ab- 

 domen are blacker and, as in some S tS. pomum, the first dorsal seg- 

 ment in % is lightly tipped with yellow. Length $ 0.18 — .19, % 0.17 

 inch. Br. wings 9 0.40 — .42, S 0.36 inch." 



Kock Island, 111. 



One % , two 9 bred from Cecidomyidous gall S. sfrohiloidcs, 0. S., 

 April 7 — 8, and consequently they appear to be inquilinous. 



4.3. Nematus trivittatus, n. sp. 



Color greenish-white ; a spot on vertex, and three vittse on tliora.K black : an- 

 tennae long and slender. Length 0.28. Br. wings 0.02 inch. 



9 . Body Stout; antenu;e black above, pale beneath, nearly as long 

 as body, slender, cylindrical, slightly enlarged at ti])s, third and fourth 

 joints equal; head as in uV. rntcj/er ; nasns with a wide eniargination ; 

 a spot on vertex, and three vitt;x) on the lobes of mesothorax black; a 

 deep groove on anterior lobe; scutel and abdomen pale greenish (some- 

 times reddish-yellow) ; legs pale, apical joints of tarsi fuscous; inner 

 claw tooth large and near the tip. Wings perfectly hyaline, stigma, 

 costa and nervurcs of apical half greenish or brownish, of basal half 

 blackish. 



Mackenzie Biver and (xreat Slave liuke, Hudson's Bay Territory, 

 (Kennicott, Smiths. Inst.) Illinois, (Coll. Am. Ent. Soc). 



Three specimens. One from Fort Resolution, Great Slave Lake, 

 has the a tenn;c a little shorter and two or three small black spots at 

 the base of the abdomen. 



