r>4 (OWA ACADKMV OF SCI F.XCKS. 



six-te'iitlis oi an iiicli in length ; color of h(>a(l and tiiorax 

 (>Iack, fadinii- into hrown : ahdonion a shinini;- hrown, darkest 

 al)ovc; scntcHnni with two i)its at Uasc; aiffeiui.a\ \o-}o\nted. 

 Malt' nol kiiow!!. 



BioHiiza nihinus, n. sp. 'J'hc o-alls appear in th(^ fall on 

 tlio leaves (.f tlie white oixk { Q. alba), :i little before the 

 foiiaiic heoins to turn dark hrown. They are sub-o-lohular in 

 form, and while g-rowino- are rosy in color (sometimes almost 

 white), and are translucent and pulpy like a _o-reen urape. 

 L!iri»'e specimens measure one-eiorhth of an inch in diameter. 

 After reachiuii" their lirowth, the <ralls turn brown and be- 

 come only a thin shell which is very smooth and glossy next 

 to the leaf. The mature gall is somewhat flattened a1)ove 

 and below. I ha\'e found this gall quite common l)otli in 

 Michigan and Iowa. The flies emerge late the following sum- 

 mer. The fly is about six-tenths of an inch in length, is shin- 

 ing l)lack in color, and has on the joints of the legs a yellow- 

 ish-brown. When highly magnified, the body appears to he 

 covered with minute scales. The fly is sparsely haired ; an- 

 ten7irE, 18-jointed: para[)sidal grooves shallow ;ind indistinct: 

 seutellnm with two shallow [)its at the base. Males not 

 knoAvn. 



Holcasjns hasettn, n, s[). The gall of this and of the suc- 

 ceeding species I have taken on the SAvam[) white oak ( Q. hi- 

 vAor) only, 1)ut have no doubt but what they also occur on 

 the bun- oak {Q. macrocarpa). The i^-alls of II. I)ass('(H/ are 

 usuallv found in clusters of from two to thirty or more 

 crowded together al)out small liml)s. The galls, unless 

 pressed out of sliape in the cluster, are sub-globular in out- 

 line with a stout teat-like projection whicli s^cms to be a 

 drawn out portion of the substance of the gall. Medium 

 sized galls measure five-eights of an in<'h in diameter. The 

 gall is composed of a corky substance, and has an egf>--shape(l 

 central cell that is easily removed by cutting ojx'u the gall. 



