104 



THE AMERICAN ENTOMOLOGIST. 



The Bastakd Oak-aitle (Q. inanis, Osteii 

 Sacken, Fig. 79), matures like the preeediug- in 

 June, but is found exclufsively npou the Red 

 Oak (quercus rubra). It diflfers from the pre- 

 ceding in never reaching so large a size, in the 

 central cell not beijig woody, but consisting of 

 a mere shell which can be readily broken with 

 the thumb-nail, and in its being only connected 

 with the external rind by slender radiating lila- 

 ments. Males and females {Cynijis q. inanis, 

 O. S.) absolutely undistinguishablo from the 



[Fig. 79.] 



Color — Drab . 



sjn-iug form of the preceding are attainable from 

 tliis gall in June ; but after repeated trials we 

 have never succeeded in breeding from it a single 

 autumnal female, and wo do not believe that 

 any .such form exists in this species. Hence, 

 and also in consequence of the very great dis- 

 similarity of the galls, and their always grow- 

 ing upon distinct species of oak, we are com- 

 pelled to consider these two gall-tiies as distinct 

 species, although when placed side by side the 

 forms generated in the spring are exactly like 

 each other. 

 TiiK Oak-i'luji Gall* (b^ig. 80 «) is remark- 



[Fig. 80.] 



J 



Color— Mottled with yellow and crimson. 



•Firstdescribeaby til e senior Editor under tlie nume 'of 

 qu.emi.1 piunm iu Proc. But. Soc. Phil. LIT p. 639, note./ ' 



able for being tlie only American gall that is 

 known to grow out ot (he acorn. It occurs in- 

 discriminately ujioii Black and Eed Oak, I'each- 

 ing maturity in August and September. At 

 that period it is solid but fleshy, and when cut 

 into is of a pink color inside shading into yellow 

 towards the middle. Subsequently, as it dries, 

 it becomes so hard as fo be cut with ditiiculty, 



IFig. si] 



^ 



Color— IJluek. 



its color inside changing, first to blood-red and 

 afterwards to bi-owii. The insect that produces 

 this gall (Cj/ni/JK q. prunus, new species, Fig. 

 81), makes its tippearance in April, and is 

 remarkable for lying two years in the gal! 

 before it eats its way out, remaining in the larva 

 state for over a year: indeed some of them re- 

 main in the larva state for over two years, aud 

 do not eat their way out until Ihc end of the 

 third year.* Figure 80, i/, shows tliis same gall 

 when cut open, and figure 80, c, the central cell 

 inhabited by the larva. 



•These galls were found fully matured and in large umn- 

 bers in August and September, 1864. In lleeember, 18B4, 

 and in April, May, June and July, 1865, the insect was still 

 in the larva state.' In October, 1865, out of '28 galls that were 

 cut open, 15 contained the larva, and 13 the perfect gall-fly. 

 Of these larvte 12 were re-enclosed in their galls. In April 

 and September, 1866, Ihcy were still in the larva state, and it 

 was not till April li, 1867, that a single-winged fly ate its 

 way out of a gall. On cutting into the gall Irora which it 

 had emerged, the cell was found half full of excrement, 

 showing thatthelarva hail " fed up " since 186.^. We annex 

 a des;cription of the perfect fly produced from this gall, as the 

 species is new to scienct' . 



CysiPS Q. PRUNUS, 11. sp. 5 Black. Head rather coarsely 

 rugoso-pmictate ; face pubescent ; antenna! rather more than 

 half as long as the bodv, 13-iointed, joint 13 equal in length 

 to joints 11 and 12 ii'ut together. Thorax opaquely and 

 coarsely i-ugoso-punctate, not so coarsely as in C. q. spongi- 

 fica, hut very much more so than in C. q. globulus; dorsal 

 groove only extending one-third of the way to the scutel, and 

 the parallel carinie on each side of it only one-half way to the 

 scutel . Soutellar fovea; very large and deep, highly polished 

 and separated only by an acute and lofty carina. Abdomen 

 with thelargeor second joint polished, and with some sparse, 

 rather large, shallow punctures upon its basal three-fourths ; 

 its terminal one-fourth, except the extreme edge, so densely 

 covered with small confluent punctures as to appear like 

 virgin silver. The whole of joints 3-7 sculptured like 

 the terminal one-fourth of joint 2. Legs rufous, the 

 ooxic, trochanters and tarsal tips black. Wiiuis subhyaline, 

 with a dark brown cloud extending from the first transverse 

 vein over the areolet and the radial area to the tip of the 

 wing. Veins all brown and distinct, hut neither the subcos- 

 tal, radial, cubital, nor anal veins attaining the exterior 

 margin. Length g 0.20— 9. 30inch. KxpanseO. 47— 0.65 inch. 



Dejcrihed from 11 $ specimens; ^ imknowu. Differs 

 from all described N. A. species by the beautifully opaqne 

 punctuation, entirely unaccompanied by any pubescence, 

 of the tip of the abdomen. 



