12 BULLETIN UNITED STATES GEOLOGICAL SUEVEY. [Voir. 



as tlie first week iu July, and tliese late galls, as well as tlie insects witliin 

 them, are generally more yellowish than those found earlier in the year; 

 hut a careful study of the structure of the inmates shows th.em to he 

 identical with those found iu the earlier galls, and these late galls are, 

 from present knowledge, to be attributed to the work of late hatching 

 and late developing stem-mothers rather than to the Avork of the third 

 generation. I am inchned to think that this third generation mil be 

 found to have a different habit, possibly feeding upon some other part of 

 the tree, without forming galls, and j)roducing in time the true sexual 

 individuals, something as in the case of the seventh generation of 8. 

 amerieana. At all events, the true female (Fig. 2, &), with the solitary egg, 

 is to be found about the trunk of the tree, as already described. 



DBSCKIPTIVE. 



COLOPHA. TJLMICOLA. 



Byrsocrypta ulmicola, Fitch, 4tli. IST. Y. Hop. 1858, p. 63 (§ 347). — Thelaxes ulmicola, Walsli, 

 Proo. Ent. Soc. Phil. vol. i, p. 305, 1862 ; American Entomologist, vol. i, p. 108, 1869.— 

 Colopha ulmicola, Monell, Canadian Entomologist, vol. ix, p. 102, 1877. 



Impregnated or ivinter egg (Fig. 2, &). — Lengtli 0.38™™, j)erfectly ovoid, sliining oliva- 

 ceous, inclining, to brown, witli no particular sculpture. 



First generation, or stem-motJier. — 0.4™™ long "when liatched. Antennae 4-jointed, joints 

 subequal in lengtli and tliickness, but with, the bases of hairs rather strong. Promnscis 

 very short., reachiug only to middle coxae or a little beyond. Ujjper tarsal hairs globate 

 at tip and as long as tarsus. Smooth, dark olive-brown in color with black members. 

 After first molt, the beak is stiU relatively shorter, as also the tarsal hairs ; the color 

 is x^aler, but the members are still black. She measures 1™™ in length when beginning 

 to bear, and the third joint of antennae is then somewhat clavate (Fig. 2, g), and as long 

 as joints 1 and 2 together ; the 4th narrower, as long as 3d, and rather truncate at tip, 

 Avith two rather consiiicuous piliferous prominences. Color translucent yelloAvish- 

 green, often inclining to purple. 



Second generation. — 0.4™™ long when born (Fig. 2, c); nearly five times as long as 

 wide ; the antennae (Fig. 2, /^) short and 5-jointed, the joints subequal in length, the 

 3d shortest and narrowest, the 5th swollen and sub-fusiform, with rather strong 

 bulbs at the base of the hairs. Promuscis reaching to hind coxae. Distinct globate tips 

 to the four tarsal hairs. Color pale olive-green, with black members and a dusky 

 striiie on the notitm. Piqm (Fig. 2, d) with antennae smooth, 6-jointed, joints sub- 

 equal in thickness, joint 4 only as long as 2; 5 and 6 each twice as long; 3 four 

 times as long. Color dingy orange, with a paler band around the thorax, embrac- 

 ing the Aving-pads, and reminding one, on this account, of the puj^a of Phylloxera. 

 Winged female (Fig. 2, e) : Average expanse 3.7™™; the form of body more as in Phylloxera, 

 the abdomen taiiering and naiTower than the thorax, bearing from ten to twenty pseud- 

 ova. Blackish, with an olive-green tint, the abdomen and under surface yellowish- 

 green in the fresher individuals. Antennae (Fig. 2, /) reaching only to insertion of 

 front wings, 6-jointed; joints 4, 5, and 6 subequal, and together equal to 3 in length. 

 [Three specimens exaimined have joints 4 and 5 very imperfectly separated, causing 

 the antennae to appear as 5-jointed. ] Wings as described by AVaLsh, the stigma being 

 well rounded and pale. [In three specimens examined, the third discoidal of the front 

 wing is simple and precisely as in PemjMgus ; in one specimen, the first discoidal is 

 wanting on both front Avings, and in another the fork of third discoidal is wanting on 

 the left one. ] Basal joint of tarsus rather short ; tarsal claws only moderately strong. 

 Third generation. — The young from the winged female, after being freed from the 

 pellicle in which they were born, have stout five-jointed antennae, the joints subequal ; 



