MEMOIRS OF THE NATIONAL ACADEMY OF SCIEXCES. 



145 



Pupa. — r>o(ly stdut ami thick, not taiieriiig imu'li to tlie end. .Siirlacc of the alxlominal 

 segments moderately punctured, the two last segments quite smooth. The cremaster ends in a 

 conical stout spine, broad at the base and shaip at the end, the point terminafirig in an unusual 

 liind of armature which, seen from above or beneath, consists of four laterally ladiating, slightly 

 uiiturued, stout spinules, the lower ones considerably smaller than the distal ones. Length, 

 2-2-23 mm. 



Habits. — The caterpillar is most commonly found on the oak. Dr. Harris found it on the 

 oak, the moth occurring June 20. By the ndddle or last of September, in New iMigland (Maine 

 and lUiode Island), it begins to pupate, nor spinning a cocoon, and jirobably entering the ground 

 before assuming the chrysalis state. In I'rovideuce it occurred on the white oak, in Maine on the 

 red oak. In Georgia, according to Smith and Abbot, it ''feeds on the chestnut oak and other 

 oaks. It went into the ground October 10 and came out ^larcli 13. Another went in June 1 and 

 came out the 19th of the same mouth." It is therefore double-brooded in tlie Gulf States and 

 single brooded in the North. The following notes on 

 its habits have been given us by Professor liiley: 



A pair of this ninth were taken M.Ty -, 1S82. from the eggs 

 of which larval hatched on the 9th. They went tlirongh their \( 1/ * 



first molt May 15; seeoiiil, May 22; third, May 26, and fourth, 

 May 31. Puiiated June 12 to 14. The moths issued from .fuue 

 2G to .Iiily 10, Several larvif'of this moth were found by beat- 

 ing on oak .liine 26 and July 10, 1882. The larvie are now very 

 plentiful and of all sizes, on several oaks. (5th Rep. U. S. 

 Ent. Comin.) 



Food plants. — Oak (Querctisof different species), 

 majile (Lintner), maple, white birch, sugar i)lum 

 (Dyar). (The statentent in my Forest Insects, p. 41-1, 

 that Mr. Eeed had found it on the maple, is an error.) 



Geoi/rophical ili.'iTriliHtion. — Eanges from Maiue 

 and Canada northward to Oregon and California, 

 occurring southward on the Atlantic and Gulf coasts to Florida, Georgia, and Texas. 



Amherst, Mass. (Mrs. Fernald). 1 have a S collected June 21 on the Vermejo Eiver, 

 northeastern New Mexico, by Lieut. W. L. Carpenter, of the Wheeler survey. Plattsburg, N. Y. 



marked success. A series calculated with the ratio 0..55 would give 0.41, 0.75, 1.27, 2.30, 4.3, and one with the ratio 

 0.73 or thereabout would interpolate a term between each one and give 0.41, 0..55, 0.75, 0.96, 1.27, 1.7, 2.3, 3.15, 4.3. 

 Thus it might be, considered either that the species normally had eight stages (ratio, 0.73) and omitted the second and 

 fourth normal stages, or that it had normally live stages (ratio, 0..55), l)ut interpolated a stage between the third and 

 fourth normal stages, and reduced the measurement in the last stage to correspond with the ratio between those 

 that immediately preceded it. The latter seems the more probable, but the fact is that the growth of the head at 

 the first and second molts is double what it is at the third, fourth, and fifth. It is a curious case. 



yiiclalii oreiioiienxis Butler. 



This was described as a variety of X doiibledai/i Pack. ; but Mr. Butler writes me under date of .Tune 30, 1892: 

 "The types « < * have pale creamy buff-colored palpi ; quite uniform in tint » * * if there is a brown line 

 above it must be on the second joint, but I do not think there is one » ' » looking at the moth without a lens 

 you would say the fringe was dark ferruginous on primaries » » » and white tijjped on interspaces." These 

 are the characters used to separate -V. gibbosa from D. doiibledaiji in Dr. Packard's description, and Mr. Butler's words 

 show that his form is not a variety of -V. doabledaiji, but the same as Hy. Edwards's J\". behreiisii. 

 1881— Butler, Ann. and Mag. Nat. Hist., p. 317. 

 bchrensii Hy. Edwards. 

 1885— Hy. Edw., Ent. Amer., i, 49. 

 Eijii. — Rather more than hemispherical, the base flattened; smooth, not shiny, white with a yellowish tinge; 

 diameter, 1.2 mm. I'nder a, microscope the surface is seen to be covered with very slight, obscure, rounded dejires- 

 sions, but, is in fact, almost smooth. 



Laid singly on the underside of the leaves of its food plants in early summer. 



Xormat Stage I (first larval stage). — Head slightly bilobed, rounded, shining pale greenish with a few hairs; 

 mouth brownish, ocelli black; width, 0.75 mm. Body slender, no tubercles or humps: feet normal, smooth, shiny, 

 .pale yellowish green. Seta' minute, rather long but not evident, color blackish. As the stage advances great 

 S. Mis. 50 10 



Fig. 6^5.— Piip;i of Xadata gibbosa. 



